[compiler-rt] compiler-rt/arm: Check for overflow when adding float denorms (PR #185245)

[via llvm-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Linux-->
# :penguin: Linux x64 Test Results

* 6449 tests passed
* 1286 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### Builtins-x86_64-linux
<details>
<summary>Builtins-x86_64-linux.Builtins-x86_64-linux/addsf3_test.c</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 5
/home/gha/actions-runner/_work/llvm-project/llvm-project/build/./bin/clang   -gline-tables-only  -m64 -DCOMPILER_RT_HAS_FLOAT16  -fno-builtin -I /home/gha/actions-runner/_work/llvm-project/llvm-project/compiler-rt/lib/builtins -nodefaultlibs /home/gha/actions-runner/_work/llvm-project/llvm-project/compiler-rt/test/builtins/Unit/addsf3_test.c /home/gha/actions-runner/_work/llvm-project/llvm-project/build/./lib/../lib/clang/23/lib/x86_64-unknown-linux-gnu/libclang_rt.builtins.a -lc -lm -o /home/gha/actions-runner/_work/llvm-project/llvm-project/build/runtimes/runtimes-bins/compiler-rt/test/builtins/Unit/X86_64LinuxConfig/Output/addsf3_test.c.tmp &&  /home/gha/actions-runner/_work/llvm-project/llvm-project/build/runtimes/runtimes-bins/compiler-rt/test/builtins/Unit/X86_64LinuxConfig/Output/addsf3_test.c.tmp
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/./bin/clang -gline-tables-only -m64 -DCOMPILER_RT_HAS_FLOAT16 -fno-builtin -I /home/gha/actions-runner/_work/llvm-project/llvm-project/compiler-rt/lib/builtins -nodefaultlibs /home/gha/actions-runner/_work/llvm-project/llvm-project/compiler-rt/test/builtins/Unit/addsf3_test.c /home/gha/actions-runner/_work/llvm-project/llvm-project/build/./lib/../lib/clang/23/lib/x86_64-unknown-linux-gnu/libclang_rt.builtins.a -lc -lm -o /home/gha/actions-runner/_work/llvm-project/llvm-project/build/runtimes/runtimes-bins/compiler-rt/test/builtins/Unit/X86_64LinuxConfig/Output/addsf3_test.c.tmp
# .---command stderr------------
# | /home/gha/actions-runner/_work/llvm-project/llvm-project/compiler-rt/test/builtins/Unit/addsf3_test.c:15:1: error: unknown type name 'COMPILER_RT_ABI'
# |    15 | COMPILER_RT_ABI float __addsf3(float a, float b);
# |       | ^
# | 1 error generated.
# `-----------------------------
# error: command failed with exit status: 1

--

```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/185245