Introduce the virtual method Decl::getPrimaryDecl().

When a Decl subclass can have multiple re-declarations in the same declaration context (like FunctionDecl),
getPrimaryDecl() will return a particular Decl that all of them will point to as the "primary" declaration.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@74800 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed