Stop spurious "DW_AT_specification(0x%8.8x) has no decl" warnings that were...

Stop spurious "DW_AT_specification(0x%8.8x) has no decl" warnings that were due to not parsing the function types when the function blocks are made and parsed. 

Cached the Function object's m_type value after it has been calculated.

llvm-svn: 141225