[clang] [llvm] [SystemZ][z/OS] Fix zos_translation_time module flag (PR #210058)

[Sean Perry via cfe-commits]

perry-ca wrote:

> I created this PR to limit the testcase to z/OS #210341. This is causing errors on arm due to the max limit being different `error: environment variable 'SOURCE_DATE_EPOCH' ('253402300799') must be a non-negative decimal integer <= 2147483647`

I'd just make this unsupported on arm since it hasn't solved the Y38 problem.

https://github.com/llvm/llvm-project/pull/210058