[clang] [Sema] Fix format-strings test on AIX (PR #180566)

[Michał Górny via cfe-commits]

mgorny wrote:

Sorry to be late to the party but this change breaks tests on 32-bit x86 Linux:

```
FAIL: Clang :: Sema/format-strings.c (19698 of 24038)
******************** TEST 'Clang :: Sema/format-strings.c' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
/var/tmp/portage/llvm-core/clang-23.0.0.9999/work/x/y/clang-abi_x86_32.x86/bin/clang -cc1 -internal-isystem /var/tmp/portage/llvm-core/
clang-23.0.0.9999/work/x/y/clang-abi_x86_32.x86/bin/../../../../lib/clang/23/include -nostdsysteminc -fblocks -fsyntax-only -verify -Wf
ormat-nonliteral -isystem /var/tmp/portage/llvm-core/clang-23.0.0.9999/work/clang/test/Sema/Inputs /var/tmp/portage/llvm-core/clang-23.
0.0.9999/work/clang/test/Sema/format-strings.c
# executed command: /var/tmp/portage/llvm-core/clang-23.0.0.9999/work/x/y/clang-abi_x86_32.x86/bin/clang -cc1 -internal-isystem /var/tm
p/portage/llvm-core/clang-23.0.0.9999/work/x/y/clang-abi_x86_32.x86/bin/../../../../lib/clang/23/include -nostdsysteminc -fblocks -fsyn
tax-only -verify -Wformat-nonliteral -isystem /var/tmp/portage/llvm-core/clang-23.0.0.9999/work/clang/test/Sema/Inputs /var/tmp/portage
/llvm-core/clang-23.0.0.9999/work/clang/test/Sema/format-strings.c
# .---command stderr------------
# | error: 'expected-warning' diagnostics expected but not seen: 
# |   File /var/tmp/portage/llvm-core/clang-23.0.0.9999/work/clang/test/Sema/format-strings.c Line 990: format specifies type 'size_t' 
(aka '{{.+}}') but the argument has type '_Bool'
# |   File /var/tmp/portage/llvm-core/clang-23.0.0.9999/work/clang/test/Sema/format-strings.c Line 991: format specifies type 'ptrdiff_
t' (aka '{{.+}}') but the argument has type '_Bool'
# | 2 errors generated.
# `-----------------------------
# error: command failed with exit status: 1

--

********************
```

https://github.com/llvm/llvm-project/pull/180566