pass a decl into diagnostic generation directly, instead of passing in the

decl loc, this simplifies code and can theoretically handle deserialized
decls better.  Noticed by inspection, NFC.

Author: lattner

Diff for: lib/Sema/TypeCheckConstraints.cpp

@@ -474,7 +474,7 @@ resolveDeclRefExpr(UnresolvedDeclRefExpr *UDRE, DeclContext *DC) {
       assert(D->getDeclContext()->isLocalContext());
       if (!D->isInvalid()) {
         diagnose(Loc, diag::use_local_before_declaration, Name);
-        diagnose(D->getLoc(), diag::decl_declared_here, Name);
+        diagnose(D, diag::decl_declared_here, Name);
       }
       return new (Context) ErrorExpr(UDRE->getSourceRange());
     }

Diff for: lib/Sema/TypeCheckExpr.cpp

@@ -846,9 +846,7 @@ namespace {
 
               TC.diagnose(NTD->getLoc(), diag::type_declared_here);
 
-              TC.diagnose(D->getLoc(), diag::decl_declared_here,
-                          D->getFullName());
-
+              TC.diagnose(D, diag::decl_declared_here, D->getFullName());
               return { false, DRE };
             }
           }
@@ -926,7 +924,7 @@ namespace {
               prevDecl = path;
             }
           }
-          TC.diagnose(capturedDecl->getLoc(), diag::decl_declared_here,
+          TC.diagnose(capturedDecl, diag::decl_declared_here,
                       capturedDecl->getFullName());
         }
         return false;