We can't pass Objective-C methods as branch arguments

Author: aschwaighofer

lib/SIL/SILVerifier.cpp

@@ -4004,6 +4004,13 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
     require(!(isa<MethodInst>(branchArg) &&
               cast<MethodInst>(branchArg)->getMember().isForeign),
         "branch argument cannot be a witness_method or an objc method_inst");
+    require(!(branchArg->getType().is<SILFunctionType>() &&
+              branchArg->getType()
+                      .castTo<SILFunctionType>()
+                      ->getExtInfo()
+                      .getRepresentation() ==
+                  SILFunctionTypeRepresentation::ObjCMethod),
+            "branch argument cannot be a objective-c method");
     return branchArg->getType() == bbArg->getType();
   }