[llvm] [mips][micromips] Add mayRaiseFPException to appropriate instructions, mark all instructions that read FCSR (FCR31) rounding bits as doing so (PR #170322)

[via llvm-commits]

github-actions[bot] wrote:

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

* 166625 tests passed
* 2895 tests skipped
* 1 test failed

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

### LLVM
<details>
<summary>LLVM.DebugInfo/MIR/Mips/live-debug-values-reg-copy.mir</summary>

```
Exit Code: 2

Command Output (stdout):
--
# RUN: at line 1
/home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/llc -run-pass=livedebugvalues /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/DebugInfo/MIR/Mips/live-debug-values-reg-copy.mir -o - | /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/DebugInfo/MIR/Mips/live-debug-values-reg-copy.mir
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/llc -run-pass=livedebugvalues /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/DebugInfo/MIR/Mips/live-debug-values-reg-copy.mir -o -
# .---command stderr------------
# | error: /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/DebugInfo/MIR/Mips/live-debug-values-reg-copy.mir:185:48: missing implicit register operand 'implicit $fcr31'
# |     renamable $d0_64 = CVT_D64_S renamable $f12, debug-location !19
# |                                                ^
# | 
# `-----------------------------
# error: command failed with exit status: 1
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/DebugInfo/MIR/Mips/live-debug-values-reg-copy.mir
# .---command stderr------------
# | FileCheck error: '<stdin>' is empty.
# | FileCheck command line:  /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/DebugInfo/MIR/Mips/live-debug-values-reg-copy.mir
# `-----------------------------
# error: command failed with exit status: 2

--

```
</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/170322