[clang] [ASTWriter] Do not allocate source location space for module maps used only for textual headers (PR #116374)

[Ilya Biryukov via cfe-commits]

ilya-biryukov wrote:

@jansvoboda11 friendly ping. We need this internally to relieve the pressure from the source location exhaustions happening on our side and it'd be great to land it.
I am certain your concerns are addressed, but maybe you had other comments.

https://github.com/llvm/llvm-project/pull/116374