Fix corner cases in compound initializer checking
Fix corner cases in compound initializer checking

Compound array and structure initializer lists with complex combinations of
designated and undesignated elements now type check. The bulk of Linux
2.6.24.3 now goes through with only one error.

darcs-hash:524c7ace6930c0674abbf97e5359195f762bd650

micknelso/language-c,micknelso/language-c,micknelso/language-c