Modify some deleted function methods to better reflect reality:

 - New isDefined() function checks for deletedness
 - isThisDeclarationADefinition checks for deletedness
 - New doesThisDeclarationHaveABody() does what
   isThisDeclarationADefinition() used to do
 - The IsDeleted bit is not propagated across redeclarations
 - isDeleted() now checks the canoncial declaration
 - New isDeletedAsWritten() does what it says on the tin.
 - isUserProvided() now correct (thanks Richard!)

This fixes the bug that we weren't catching

void foo() = delete;
void foo() {}

as being a redefinition.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@131013 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 2b82f90..44b8c6a 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -1385,7 +1385,7 @@
     return Var->isFileVarDecl() &&
            Var->isThisDeclarationADefinition() == VarDecl::Definition;
   if (FunctionDecl *Func = dyn_cast<FunctionDecl>(D))
-    return Func->isThisDeclarationADefinition();
+    return Func->doesThisDeclarationHaveABody();
   return isa<ObjCProtocolDecl>(D) || isa<ObjCImplementationDecl>(D);
 }