[PATCH] Diagnose the usage of an MS inline assembly label not defined in the same assembly block

[Ehsan Akhgari]

Playing with the idea of checking these LabelDecl's at the end of the function, here's another issue I just thought about.  At the end of the function we will know which MSAsmStmt has defined a given LabelDecl, but how do we know which LabelDecl has *used* it?  Should I record that info in LabelDecl too?

http://reviews.llvm.org/D5694