[mips] [IAS] Add missing constraints and improve testing for the .module directive.

Summary:
None of the .set directives can be used before the .module directives. The .set mips0/pop/push were not triggering this constraint.
Also added testing for all the other implemented directives which are supposed to trigger this constraint.

Reviewers: dsanders

Reviewed By: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D7140

llvm-svn: 231465