[compiler-rt] [compiler-rt] Fix definition of `usize` on 32-bit Windows (PR #106151)

[Alexander Richardson via llvm-commits]

arichardson wrote:

@mstorsjo @zmodem This new minimally invasive version should fix the build breakage - I'll work on cleaning up these typedefs properly in https://github.com/llvm/llvm-project/pull/106155. Please let me know if this fixes the issue.

https://github.com/llvm/llvm-project/pull/106151