[clang] [clang][ItaniumMangle] Fix mangling of lambdas in default member initializers of local classes (PR #206740)

[via cfe-commits]

github-actions[bot] wrote:

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

* 88487 tests passed
* 1702 tests skipped
* 1 test failed

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

### Clang
<details>
<summary>Clang.CodeGenCXX/mangle-lambdas-in-dmi-local-class.cpp</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
/home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/clang -cc1 -internal-isystem /home/gha/actions-runner/_work/llvm-project/llvm-project/build/lib/clang/23/include -nostdsysteminc -triple x86_64-linux-gnu /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CodeGenCXX/mangle-lambdas-in-dmi-local-class.cpp -emit-llvm -I/home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CodeGenCXX -std=c++20 -o - | /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CodeGenCXX/mangle-lambdas-in-dmi-local-class.cpp
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/clang -cc1 -internal-isystem /home/gha/actions-runner/_work/llvm-project/llvm-project/build/lib/clang/23/include -nostdsysteminc -triple x86_64-linux-gnu /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CodeGenCXX/mangle-lambdas-in-dmi-local-class.cpp -emit-llvm -I/home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CodeGenCXX -std=c++20 -o -
# note: command had no output on stdout or stderr
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CodeGenCXX/mangle-lambdas-in-dmi-local-class.cpp
# .---command stderr------------
# | /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CodeGenCXX/mangle-lambdas-in-dmi-local-class.cpp:60:11: error: CHECK: expected string not found in input
# | // CHECK: store ptr @_ZTIZ3foovEN4Test1aMUlvE_E
# |           ^
# | <stdin>:35:32: note: scanning from here
# |  call void @_ZZ3foovEN4TestC2Ev(ptr noundef nonnull align 8 dereferenceable(16) %this1) #1
# |                                ^
# | <stdin>:45:7: note: possible intended match here
# |  call void @_ZZ3foovEN4TestC2E_0v(ptr noundef nonnull align 8 dereferenceable(16) %this1) #1
# |       ^
# | 
# | Input file: <stdin>
# | Check file: /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CodeGenCXX/mangle-lambdas-in-dmi-local-class.cpp
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |             .
# |             .
# |             .
# |            30: define internal void @_ZZ3foovEN4TestC1Ev(ptr noundef nonnull align 8 dereferenceable(16) %this) unnamed_addr #0 align 2 { 
# |            31: entry: 
# |            32:  %this.addr = alloca ptr, align 8 
# |            33:  store ptr %this, ptr %this.addr, align 8 
# |            34:  %this1 = load ptr, ptr %this.addr, align 8 
# |            35:  call void @_ZZ3foovEN4TestC2Ev(ptr noundef nonnull align 8 dereferenceable(16) %this1) #1 
# | check:60'0                                   {                                                              search range start (exclusive)
# | check:60'1                                                                                                  error: no match found in search range
# |            36:  ret void 
# |            37: } 
# |            38:  
# |            39: ; Function Attrs: mustprogress noinline nounwind optnone 
# |            40: define internal void @_ZZ3foovEN4TestC1E_0v(ptr noundef nonnull align 8 dereferenceable(16) %this) unnamed_addr #0 align 2 { 
# |            41: entry: 
# |            42:  %this.addr = alloca ptr, align 8 
# |            43:  store ptr %this, ptr %this.addr, align 8 
# |            44:  %this1 = load ptr, ptr %this.addr, align 8 
# |            45:  call void @_ZZ3foovEN4TestC2E_0v(ptr noundef nonnull align 8 dereferenceable(16) %this1) #1 
# | check:60'2           ?                                                                                        possible intended match
# | check:60'3                                      }                                                             search range end (exclusive)
# |            46:  ret void 
# |            47: } 
# |            48:  
# |            49: ; Function Attrs: mustprogress noinline nounwind optnone 
# |            50: define internal void @_ZZ3foovEN4TestC2Ev(ptr noundef nonnull align 8 dereferenceable(16) %this) unnamed_addr #0 align 2 { 
# |             .
# |             .
# |             .
# | >>>>>>
# `-----------------------------
# 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/206740