[clang] [clang][analysis] Fix flaky clang/test/Analysis/live-stmts.cpp test (PR #126913)

[Balazs Benics via cfe-commits]

steakhal wrote:

> Unfortunately the test still seems to be flaky. With EXPENSIVE_CHECKS I often see it fail on the RHEL8 x86_64 machines I use.
> E.g.
> ```
> FAIL: Clang :: Analysis/live-stmts.cpp (1 of 1)
> ******************** TEST 'Clang :: Analysis/live-stmts.cpp' FAILED ********************
> Exit Code: 1
> 
> Command Output (stderr):
> --
> RUN: at line 1: /repo/uabelho/main-github/llvm/build-all-expensive/bin/clang -cc1 -internal-isystem /repo/uabelho/main-github/llvm/build-all-expensive/lib/clang/21/include -nostdsysteminc -analyze -analyzer-constraints=range -setup-static-analyzer -w -analyzer-checker=debug.DumpLiveExprs /repo/uabelho/main-github/clang/test/Analysis/live-stmts.cpp 2>&1   | /repo/uabelho/main-github/llvm/build-all-expensive/bin/FileCheck /repo/uabelho/main-github/clang/test/Analysis/live-stmts.cpp
> + /repo/uabelho/main-github/llvm/build-all-expensive/bin/clang -cc1 -internal-isystem /repo/uabelho/main-github/llvm/build-all-expensive/lib/clang/21/include -nostdsysteminc -analyze -analyzer-constraints=range -setup-static-analyzer -w -analyzer-checker=debug.DumpLiveExprs /repo/uabelho/main-github/clang/test/Analysis/live-stmts.cpp
> + /repo/uabelho/main-github/llvm/build-all-expensive/bin/FileCheck /repo/uabelho/main-github/clang/test/Analysis/live-stmts.cpp
> /repo/uabelho/main-github/clang/test/Analysis/live-stmts.cpp:227:16: error: CHECK-EMPTY: is not on the line after the previous match
> // CHECK-EMPTY:
>                ^
> <stdin>:160:1: note: 'next' match was here
> 
> ^
> <stdin>:157:81: note: previous match ended here
> | `-DeclRefExpr 0x55e1600cec58 '_Bool' lvalue ParmVar 0x55e1600cead8 'b' '_Bool'
>                                                                                 ^
> <stdin>:158:1: note: non-matching line after previous match is here
> `-ImplicitCastExpr 0x55e1600cecb0 '_Bool' <LValueToRValue>
> ^
> 
> Input file: <stdin>
> Check file: /repo/uabelho/main-github/clang/test/Analysis/live-stmts.cpp
> 
> -dump-input=help explains the following input dump.
> 
> Input was:
> <<<<<<
>            .
>            .
>            .
>          155: BinaryOperator 0x55e1600cecc8 '_Bool' '||' 
>          156: |-ImplicitCastExpr 0x55e1600cec98 '_Bool' <LValueToRValue> 
>          157: | `-DeclRefExpr 0x55e1600cec58 '_Bool' lvalue ParmVar 0x55e1600cead8 'b' '_Bool' 
>          158: `-ImplicitCastExpr 0x55e1600cecb0 '_Bool' <LValueToRValue> 
>          159:  `-DeclRefExpr 0x55e1600cec78 '_Bool' lvalue ParmVar 0x55e1600cead8 'b' '_Bool' 
>          160:  
> empty:227     ! error: match on wrong line
>          161: ImplicitCastExpr 0x55e1600cec98 '_Bool' <LValueToRValue> 
>          162: `-DeclRefExpr 0x55e1600cec58 '_Bool' lvalue ParmVar 0x55e1600cead8 'b' '_Bool' 
>          163:  
>          164: ImplicitCastExpr 0x55e1600cecb0 '_Bool' <LValueToRValue> 
>          165: `-DeclRefExpr 0x55e1600cec78 '_Bool' lvalue ParmVar 0x55e1600cead8 'b' '_Bool' 
>            .
>            .
>            .
> >>>>>>
> 
> --
> 
> ********************
> ********************
> Failed Tests (1):
>   Clang :: Analysis/live-stmts.cpp
> ```

Oh cmmon. :(
Could you send me your nonpassing output, the whole one? @mikaelholmen 

https://github.com/llvm/llvm-project/pull/126913