Fix <rdar://problem/6265257> warnings for ambiguous message send swamp other warnings.
Reworked Sema::MatchTwoMethodDeclarations() to optionally match based on method size and alignment (the default in GCC). Changed Sema::LookupInstanceMethodInGlobalPool() to use this feature.
Added -Wno-struct-selector-match to driver, however didn't hook it up yet. Added a FIXME that says this.
llvm-svn: 57898
Long standing bug in Sema::ActOnInstanceMessage(). We now warn when messaging an "id" with multiple method signatures in scope. The diags are a little verbose, however they can be streamlined if necessary.
llvm-svn: 56843