[clang] [LifetimeSafety] Add bailout for large CFGs (PR #170444)

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github-actions[bot] wrote:

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

* 52338 tests passed
* 926 tests skipped
* 1 test failed

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

### Clang
<details>
<summary>Clang.Sema/warn-lifetime-safety-cfg-bailout.cpp</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
c:\_work\llvm-project\llvm-project\build\bin\clang.exe -cc1 -internal-isystem C:\_work\llvm-project\llvm-project\build\lib\clang\23\include -nostdsysteminc -fsyntax-only -fexperimental-lifetime-safety -Wexperimental-lifetime-safety -fexperimental-lifetime-safety-max-cfg-blocks=3 -Wno-dangling C:\_work\llvm-project\llvm-project\clang\test\Sema\warn-lifetime-safety-cfg-bailout.cpp 2>&1 | c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe C:\_work\llvm-project\llvm-project\clang\test\Sema\warn-lifetime-safety-cfg-bailout.cpp --check-prefix=CHECK-BAILOUT
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\clang.exe' -cc1 -internal-isystem 'C:\_work\llvm-project\llvm-project\build\lib\clang\23\include' -nostdsysteminc -fsyntax-only -fexperimental-lifetime-safety -Wexperimental-lifetime-safety -fexperimental-lifetime-safety-max-cfg-blocks=3 -Wno-dangling 'C:\_work\llvm-project\llvm-project\clang\test\Sema\warn-lifetime-safety-cfg-bailout.cpp'
# note: command had no output on stdout or stderr
# error: command failed with exit status: 1
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe' 'C:\_work\llvm-project\llvm-project\clang\test\Sema\warn-lifetime-safety-cfg-bailout.cpp' --check-prefix=CHECK-BAILOUT
# .---command stderr------------
# | C:\_work\llvm-project\llvm-project\clang\test\Sema\warn-lifetime-safety-cfg-bailout.cpp:29:28: error: CHECK-BAILOUT: expected string not found in input
# |  p = &s; // CHECK-BAILOUT: warning: object whose reference is captured does not live long enough
# |                            ^
# | <stdin>:1:1: note: scanning from here
# | warning: unknown warning option '-Wexperimental-lifetime-safety'; did you mean '-Wexperimental-header-units'? [-Wunknown-warning-option]
# | ^
# | 
# | Input file: <stdin>
# | Check file: C:\_work\llvm-project\llvm-project\clang\test\Sema\warn-lifetime-safety-cfg-bailout.cpp
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |           1: warning: unknown warning option '-Wexperimental-lifetime-safety'; did you mean '-Wexperimental-header-units'? [-Wunknown-warning-option] 
# | check:29     X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found
# |           2: error: unknown argument: '-fexperimental-lifetime-safety' 
# | check:29     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# | >>>>>>
# `-----------------------------
# 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/170444