[clang] clang/limits.h: Avoid including limits.h twice (PR #120526)

[via cfe-commits]

pirama-arumuga-nainar wrote:

Does this pattern still occur while doing `echo "#include <limits.h>" | clang-19 -E -O2 -xc - -MM -H`?  That is idiomatic compared to including `/usr/include/limits.h` directly.

It also doesn't seem correct to depend on the `_LIBC_LIMITS_H_` macro which is defined in glibc.

Adding @AaronBallman who will have stronger opinion around this.


https://github.com/llvm/llvm-project/pull/120526