[Attr] Fix `-ast-print` for `asm` attribute

[jdenny]

Summary

Without this fix, the tests introduced here produce the following
assert fail:

clang: /home/jdenny/llvm/clang/include/clang/Basic/AttributeCommonInfo.h:163: unsigned int clang::AttributeCommonInfo::getAttributeSpellingListIndex() const: Assertion `(isAttributeSpellingListCalculated() || AttrName) && "Spelling cannot be found"' failed.

The bug was introduced by D67368, which caused AsmLabelAttr's
spelling index to be set to SpellingNotCalculated.

[aaron.ballman]

LGTM!

clang/lib/Sema/SemaDecl.cpp

if (S->getFnParent() != nullptr) {
       }
 
       if (!R->isIntegralType(Context) && !R->isPointerType()) {
         Diag(D.getBeginLoc(), diag::err_asm_bad_register_type);
         NewVD->setInvalidDecl(true);
       }
     }
 
-    NewVD->addAttr(::new (Context) AsmLabelAttr(
-        Context, SE->getStrTokenLoc(0), Label, /*IsLiteralLabel=*/true));
+    NewVD->addAttr(AsmLabelAttr::Create(Context, Label,
+                                        /*IsLiteralLabel=*/true,
+                                        SE->getStrTokenLoc(0)));
   } else if (!ExtnameUndeclaredIdentifiers.empty()) {
     llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
       ExtnameUndeclaredIdentifiers.find(NewVD->getIdentifier());
     if (I != ExtnameUndeclaredIdentifiers.end()) {
       if (isDeclExternC(NewVD)) {
         NewVD->addAttr(I->second);
         ExtnameUndeclaredIdentifiers.erase(I);
       } else
FilterLookupForScope(Previous, OriginalDC, S, shouldConsiderLinkage(NewFD),
                        D.getCXXScopeSpec().isNotEmpty() ||
                        isMemberSpecialization ||
                        isFunctionTemplateSpecialization);
 
   // Handle GNU asm-label extension (encoded as an attribute).
   if (Expr *E = (Expr*) D.getAsmLabel()) {
     // The parser guarantees this is a string.
     StringLiteral *SE = cast<StringLiteral>(E);
-    NewFD->addAttr(::new (Context)
-                       AsmLabelAttr(Context, SE->getStrTokenLoc(0),
-                                    SE->getString(), /*IsLiteralLabel=*/true));
+    NewFD->addAttr(AsmLabelAttr::Create(Context, SE->getString(),
+                                        /*IsLiteralLabel=*/true,
+                                        SE->getStrTokenLoc(0)));
   } else if (!ExtnameUndeclaredIdentifiers.empty()) {
     llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
       ExtnameUndeclaredIdentifiers.find(NewFD->getIdentifier());
     if (I != ExtnameUndeclaredIdentifiers.end()) {
       if (isDeclExternC(NewFD)) {
         NewFD->addAttr(I->second);
         ExtnameUndeclaredIdentifiers.erase(I);
       } else

clang/test/AST/ast-print-attr.c

 // RUN: %clang_cc1 -ast-print -x objective-c++ -fms-extensions %s -o - | FileCheck %s
 
 // CHECK: using A = __kindof id (*)[1];
 using A = __kindof id (*)[1];
 
 // CHECK: using B = int ** __ptr32 *[3];
 using B = int ** __ptr32 *[3];
 
 // FIXME: This is the wrong spelling for the attribute.
 // FIXME: Too many parens here!
 // CHECK: using C = int ((*))() __attribute__((cdecl));
 using C = int (*)() [[gnu::cdecl]];
+
+// CHECK: int fun_asm() asm("");
+int fun_asm() asm("");
+// CHECK: int var_asm asm("");
+int var_asm asm("");