[clang] [llvm] DAGCombiner: Drop AllowFPOpFusion from visitFADDForFMACombine (PR #221436)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-expensive-checks-ubuntu` running on `as-builder-4` while building `clang,llvm` at step 7 "test-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/187/builds/23415

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 7 (test-check-all) failure: Test just built components: check-all completed (failure)
******************** TEST 'LLVM :: CodeGen/ARM/fp16-instructions.ll' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 2
/home/buildbot/worker/expensive-checks/build/bin/llc < /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll -mtriple=arm-none-eabi -float-abi=soft     | /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFT
# executed command: /home/buildbot/worker/expensive-checks/build/bin/llc -mtriple=arm-none-eabi -float-abi=soft
# executed command: /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFT
# RUN: at line 3
/home/buildbot/worker/expensive-checks/build/bin/llc < /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll -mtriple=thumb-none-eabi -float-abi=soft   | /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFT
# executed command: /home/buildbot/worker/expensive-checks/build/bin/llc -mtriple=thumb-none-eabi -float-abi=soft
# executed command: /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFT
# RUN: at line 4
/home/buildbot/worker/expensive-checks/build/bin/llc < /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll -mtriple=thumbv8.1m.main-none-eabi -mattr=+mve | /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFT
# executed command: /home/buildbot/worker/expensive-checks/build/bin/llc -mtriple=thumbv8.1m.main-none-eabi -mattr=+mve
# executed command: /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFT
# RUN: at line 5
/home/buildbot/worker/expensive-checks/build/bin/llc < /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll -mtriple=thumbv8.1m.main-none-eabi -float-abi=soft -mattr=+mve | /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFT
# executed command: /home/buildbot/worker/expensive-checks/build/bin/llc -mtriple=thumbv8.1m.main-none-eabi -float-abi=soft -mattr=+mve
# executed command: /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFT
# RUN: at line 8
/home/buildbot/worker/expensive-checks/build/bin/llc < /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll -mtriple=arm-none-eabi -mattr=+vfp3        | /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFTFP-VFP3
# executed command: /home/buildbot/worker/expensive-checks/build/bin/llc -mtriple=arm-none-eabi -mattr=+vfp3
# executed command: /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFTFP-VFP3
# RUN: at line 9
/home/buildbot/worker/expensive-checks/build/bin/llc < /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll -mtriple=arm-none-eabi -mattr=+vfp4        | /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFTFP-FP16,CHECK-SOFTFP-FP16-A32
# executed command: /home/buildbot/worker/expensive-checks/build/bin/llc -mtriple=arm-none-eabi -mattr=+vfp4
# executed command: /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFTFP-FP16,CHECK-SOFTFP-FP16-A32
# RUN: at line 10
/home/buildbot/worker/expensive-checks/build/bin/llc < /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll -mtriple=arm-none-eabi -mattr=+fullfp16,+fp64    | /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFTFP-FULLFP16
# executed command: /home/buildbot/worker/expensive-checks/build/bin/llc -mtriple=arm-none-eabi -mattr=+fullfp16,+fp64
# executed command: /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFTFP-FULLFP16
# RUN: at line 12
/home/buildbot/worker/expensive-checks/build/bin/llc < /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll -mtriple=thumbv7-none-eabi -mattr=+vfp3        | /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFTFP-VFP3
# executed command: /home/buildbot/worker/expensive-checks/build/bin/llc -mtriple=thumbv7-none-eabi -mattr=+vfp3
# executed command: /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFTFP-VFP3
# RUN: at line 13
/home/buildbot/worker/expensive-checks/build/bin/llc < /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll -mtriple=thumbv7-none-eabi -mattr=+vfp4        | /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFTFP-FP16,CHECK-SOFTFP-FP16-T32
# executed command: /home/buildbot/worker/expensive-checks/build/bin/llc -mtriple=thumbv7-none-eabi -mattr=+vfp4
# executed command: /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFTFP-FP16,CHECK-SOFTFP-FP16-T32
# RUN: at line 14
/home/buildbot/worker/expensive-checks/build/bin/llc < /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll -mtriple=thumbv7-none-eabi -mattr=+fullfp16,+fp64    | /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFTFP-FULLFP16
# executed command: /home/buildbot/worker/expensive-checks/build/bin/llc -mtriple=thumbv7-none-eabi -mattr=+fullfp16,+fp64
# executed command: /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK,CHECK-SOFTFP-FULLFP16
# RUN: at line 17
/home/buildbot/worker/expensive-checks/build/bin/llc < /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll -mtriple=arm-none-eabi -mattr=+fullfp16,+fp64 -O0 | /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK-SPILL-RELOAD
# executed command: /home/buildbot/worker/expensive-checks/build/bin/llc -mtriple=arm-none-eabi -mattr=+fullfp16,+fp64 -O0
# executed command: /home/buildbot/worker/expensive-checks/build/bin/FileCheck /home/buildbot/worker/expensive-checks/llvm-project/llvm/test/CodeGen/ARM/fp16-instructions.ll --check-prefixes=CHECK-SPILL-RELOAD
# RUN: at line 18
...

```

</details>

https://github.com/llvm/llvm-project/pull/221436