When running `make LLVM=1 checkstack`, OBJDUMP is set to llvm-objdump. llvm-objdump outputs disassembly with instruction size suffixes (such as subq/addq/subl/addl), tabs/whitespace differences, spaces after commas, and trailing comments (e.g. `# imm = 0x...`). Because scripts/checkstack.pl used rigid regular expressions specifically tuned to GNU objdump format (e.g. requiring exactly four spaces, no suffix, and no space after comma), checkstack.pl failed to match any stack adjustment instructions and yielded no output when using llvm-objdump on x86. Update the regular expressions for x86 to match optional suffixes, variable whitespace, and trailing comments. Link: https://lore.kernel.org/20260902-checkstack_llvm_objdump-v1-1-edb4eca5f163@google.com Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Assisted-by: LLM Gemini Cc: Bill Wendling <morbo@google.com> Cc: Justin Stitt <justinstitt@google.com> Cc: Nathan Chancellor <nathan@kernel.org>