Add a lint check for mismatched return types, inspired by PR6944.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108162 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/Lint.cpp b/lib/Analysis/Lint.cpp
index 60654e6..9f1b30d 100644
--- a/lib/Analysis/Lint.cpp
+++ b/lib/Analysis/Lint.cpp
@@ -225,6 +225,10 @@
             "Undefined behavior: Call argument count mismatches callee "
             "argument count", &I);
 
+    Assert1(FT->getReturnType() == I.getType(),
+            "Undefined behavior: Call return type mismatches "
+            "callee return type", &I);
+
     // Check argument types (in case the callee was casted) and attributes.
     // TODO: Verify that caller and callee attributes are compatible.
     Function::arg_iterator PI = F->arg_begin(), PE = F->arg_end();