[llvm] [AMDGPU][MIR] Serialize NumPhysicalVGPRSpillLanes (PR #115291)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-expensive-checks-debian` running on `gribozavr4` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/16/builds/8444

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

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: CodeGen/MIR/AMDGPU/machine-function-info-no-ir.mir' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc -mtriple=amdgcn-amd-amdhsa -run-pass=none -verify-machineinstrs /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/MIR/AMDGPU/machine-function-info-no-ir.mir -o - | /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/FileCheck -check-prefixes=FULL,ALL /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/MIR/AMDGPU/machine-function-info-no-ir.mir
+ /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/llc -mtriple=amdgcn-amd-amdhsa -run-pass=none -verify-machineinstrs /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/MIR/AMDGPU/machine-function-info-no-ir.mir -o -
+ /b/1/llvm-clang-x86_64-expensive-checks-debian/build/bin/FileCheck -check-prefixes=FULL,ALL /b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/MIR/AMDGPU/machine-function-info-no-ir.mir
/b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/MIR/AMDGPU/machine-function-info-no-ir.mir:51:14: error: FULL-NEXT: is not on the line after the previous match
# FULL-NEXT: vgprForAGPRCopy: ''
             ^
<stdin>:206:2: note: 'next' match was here
 vgprForAGPRCopy: ''
 ^
<stdin>:204:14: note: previous match ended here
 occupancy: 8
             ^
<stdin>:205:1: note: non-matching line after previous match is here
 numPhysicalVGPRSpillLanes: 0
^
/b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/MIR/AMDGPU/machine-function-info-no-ir.mir:155:14: error: FULL-NEXT: is not on the line after the previous match
# FULL-NEXT: vgprForAGPRCopy: ''
             ^
<stdin>:311:2: note: 'next' match was here
 vgprForAGPRCopy: ''
 ^
<stdin>:309:14: note: previous match ended here
 occupancy: 8
             ^
<stdin>:310:1: note: non-matching line after previous match is here
 numPhysicalVGPRSpillLanes: 0
^
/b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/MIR/AMDGPU/machine-function-info-no-ir.mir:230:14: error: FULL-NEXT: is not on the line after the previous match
# FULL-NEXT: vgprForAGPRCopy: ''
             ^
<stdin>:416:2: note: 'next' match was here
 vgprForAGPRCopy: ''
 ^
<stdin>:414:14: note: previous match ended here
 occupancy: 8
             ^
<stdin>:415:1: note: non-matching line after previous match is here
 numPhysicalVGPRSpillLanes: 0
^
/b/1/llvm-clang-x86_64-expensive-checks-debian/llvm-project/llvm/test/CodeGen/MIR/AMDGPU/machine-function-info-no-ir.mir:306:14: error: FULL-NEXT: is not on the line after the previous match
# FULL-NEXT: vgprForAGPRCopy: ''
             ^
<stdin>:521:2: note: 'next' match was here
 vgprForAGPRCopy: ''
 ^
...

```

</details>

https://github.com/llvm/llvm-project/pull/115291