[llvm] [LowerTypeTests] Avoid null dereference on invalid branch funnel operand (PR #204951)

[via llvm-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Windows-->
# :window: Windows x64 Test Results

* 138493 tests passed
* 3541 tests skipped
* 1 test failed

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

### LLVM
<details>
<summary>LLVM.Transforms/LowerTypeTests/icall-branch-funnel-invalid-operand.ll</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
not c:\_work\llvm-project\llvm-project\build\bin\opt.exe -S -passes=lowertypetests C:\_work\llvm-project\llvm-project\llvm\test\Transforms\LowerTypeTests\icall-branch-funnel-invalid-operand.ll 2>&1 | c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe C:\_work\llvm-project\llvm-project\llvm\test\Transforms\LowerTypeTests\icall-branch-funnel-invalid-operand.ll
# executed command: not 'c:\_work\llvm-project\llvm-project\build\bin\opt.exe' -S -passes=lowertypetests 'C:\_work\llvm-project\llvm-project\llvm\test\Transforms\LowerTypeTests\icall-branch-funnel-invalid-operand.ll'
# note: command had no output on stdout or stderr
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe' 'C:\_work\llvm-project\llvm-project\llvm\test\Transforms\LowerTypeTests\icall-branch-funnel-invalid-operand.ll'
# .---command stderr------------
# | C:\_work\llvm-project\llvm-project\llvm\test\Transforms\LowerTypeTests\icall-branch-funnel-invalid-operand.ll:2:10: error: CHECK: expected string not found in input
# | ; CHECK: LLVM ERROR: Expected branch funnel operand to be global value
# |          ^
# | <stdin>:1:1: note: scanning from here
# | LLVM ERROR: Expected branch funnel operand to be a defined global value with type metadata
# | ^
# | 
# | Input file: <stdin>
# | Check file: C:\_work\llvm-project\llvm-project\llvm\test\Transforms\LowerTypeTests\icall-branch-funnel-invalid-operand.ll
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |            1: LLVM ERROR: Expected branch funnel operand to be a defined global value with type metadata 
# | check:2'0    {                                                                                             search range start (exclusive)
# | check:2'1                                                                                                  error: no match found in search range
# |            2: PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug. 
# |            3: Stack dump: 
# |            4: 0. Program arguments: c:\\_work\\llvm-project\\llvm-project\\build\\bin\\opt.exe -S -passes=lowertypetests C:\\_work\\llvm-project\\llvm-project\\llvm\\test\\Transforms\\LowerTypeTests\\icall-branch-funnel-invalid-operand.ll 
# |            5: 1. Running pass "lowertypetests" on module "C:\_work\llvm-project\llvm-project\llvm\test\Transforms\LowerTypeTests\icall-branch-funnel-invalid-operand.ll" 
# | check:2'2                                                                                                                                                                } search range end (exclusive)
# | >>>>>>
# `-----------------------------
# 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/204951