[compiler-rt] [compiler-rt] Simplify and rename of operator_new_size_type (PR #83912)

[Alexander Richardson via llvm-commits]

arichardson wrote:

It looks like the problem is 

#  if (SANITIZER_WORDSIZE == 64) || SANITIZER_APPLE || SANITIZER_WINDOWS, this should not be checking SANITIZER_WINDOWS, since _WIN32 uses unsigned int not unsigned long. Will upload a PR.

https://github.com/llvm/llvm-project/pull/83912