Add '-validate-clang-modules-once' and '-clang-build-session-file' corresponding to Clang's '-fmodules-validate-once-per-build-session' and '-fbuild-session-file='. Ensure they are propagated to module interface build sub-invocations.
We require these to be first-class Swift options in order to ensure they are propagated to both: ClangImporter and implicit interface build compiler sub-invocations.
Compiler portion of rdar://105982120
