Only destroy static locals if they have non-trivial destructors.

This fixes a regression introduced in
2b4fa53 that caused us to emit
shutdown-time destruction for variables with ARC ownership, using
C++-specific functions that don't exist in C implementations.

Author: zygoloid

clang/lib/CodeGen/CGDecl.cpp

@@ -366,7 +366,8 @@ CodeGenFunction::AddInitializerToStaticVarDecl(const VarDecl &D,
 
   emitter.finalize(GV);
 
-  if (D.needsDestruction(getContext()) && HaveInsertPoint()) {
+  if (D.needsDestruction(getContext()) == QualType::DK_cxx_destructor &&
+      HaveInsertPoint()) {
     // We have a constant initializer, but a nontrivial destructor. We still
     // need to perform a guarded "initialization" in order to register the
     // destructor.

clang/test/CodeGenObjC/initialize-function-static.m

@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -triple x86_64-apple-macos10.15 -emit-llvm -fobjc-arc -o - %s | FileCheck %s
+
+@interface I
+@end
+
+I *i() {
+  static I *i = ((void *)0);
+  return i;
+}
+
+// CHECK-NOT: __cxa_guard_acquire
+// CHECK-NOT: __cxa_guard_release