[IR] Ignore globals with the `llvm.` prefix when calculating module hash

This came up in This came up in
https://reviews.llvm.org/D146776#inline-1489091 and is slightly related
to https://reviews.llvm.org/D153855. In both patches, there is the
observation that some modifications of the module should not invalidate
analysis, such as when adding a declaration or some metadata the won't
be used when compiling the current module.

This patch implements the suggestion that we should ignore globals that have
the `llvm.` prefix when calculating the module hash.

Fixes https://github.com/llvm/llvm-project/issues/63590

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D154019