Add some side-effect free Create methods for TypeDecl subclasses and use them for PCH reading.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107468 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 267c19f..c3c30f9 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -1638,6 +1638,10 @@
   return Enum;
 }
 
+EnumDecl *EnumDecl::Create(ASTContext &C, EmptyShell Empty) {
+  return new (C) EnumDecl(0, SourceLocation(), 0, 0, SourceLocation());
+}
+
 void EnumDecl::Destroy(ASTContext& C) {
   TagDecl::Destroy(C);
 }
@@ -1677,6 +1681,11 @@
   return R;
 }
 
+RecordDecl *RecordDecl::Create(ASTContext &C, EmptyShell Empty) {
+  return new (C) RecordDecl(Record, TTK_Struct, 0, SourceLocation(), 0, 0,
+                            SourceLocation());
+}
+
 RecordDecl::~RecordDecl() {
 }
 
diff --git a/lib/AST/DeclCXX.cpp b/lib/AST/DeclCXX.cpp
index 9ab44b6..a77c1c8 100644
--- a/lib/AST/DeclCXX.cpp
+++ b/lib/AST/DeclCXX.cpp
@@ -58,6 +58,11 @@
   return R;
 }
 
+CXXRecordDecl *CXXRecordDecl::Create(ASTContext &C, EmptyShell Empty) {
+  return new (C) CXXRecordDecl(CXXRecord, TTK_Struct, 0, SourceLocation(), 0, 0,
+                               SourceLocation());
+}
+
 CXXRecordDecl::~CXXRecordDecl() {
 }
 
diff --git a/lib/AST/DeclTemplate.cpp b/lib/AST/DeclTemplate.cpp
index 5984eaa..9a7bc91 100644
--- a/lib/AST/DeclTemplate.cpp
+++ b/lib/AST/DeclTemplate.cpp
@@ -266,6 +266,12 @@
   return new (C) TemplateTypeParmDecl(DC, L, Id, Typename, Type, ParameterPack);
 }
 
+TemplateTypeParmDecl *
+TemplateTypeParmDecl::Create(ASTContext &C, EmptyShell Empty) {
+  return new (C) TemplateTypeParmDecl(0, SourceLocation(), 0, false,
+                                      QualType(), false);
+}
+
 SourceLocation TemplateTypeParmDecl::getDefaultArgumentLoc() const {
   return DefaultArgument->getTypeLoc().getSourceRange().getBegin();
 }
@@ -476,7 +482,7 @@
 }
 
 ClassTemplateSpecializationDecl *
-ClassTemplateSpecializationDecl::CreateEmpty(ASTContext &Context) {
+ClassTemplateSpecializationDecl::Create(ASTContext &Context, EmptyShell Empty) {
   return
     new (Context)ClassTemplateSpecializationDecl(ClassTemplateSpecialization);
 }
@@ -545,7 +551,8 @@
 }
 
 ClassTemplatePartialSpecializationDecl *
-ClassTemplatePartialSpecializationDecl::CreateEmpty(ASTContext &Context) {
+ClassTemplatePartialSpecializationDecl::Create(ASTContext &Context,
+                                               EmptyShell Empty) {
   return new (Context)ClassTemplatePartialSpecializationDecl();
 }
 
diff --git a/lib/Frontend/PCHReaderDecl.cpp b/lib/Frontend/PCHReaderDecl.cpp
index 120596b..2bdf166 100644
--- a/lib/Frontend/PCHReaderDecl.cpp
+++ b/lib/Frontend/PCHReaderDecl.cpp
@@ -1145,11 +1145,10 @@
     D = TypedefDecl::Create(*Context, 0, SourceLocation(), 0, 0);
     break;
   case pch::DECL_ENUM:
-    D = EnumDecl::Create(*Context, 0, SourceLocation(), 0, SourceLocation(), 0);
+    D = EnumDecl::Create(*Context, Decl::EmptyShell());
     break;
   case pch::DECL_RECORD:
-    D = RecordDecl::Create(*Context, TTK_Struct, 0, SourceLocation(),
-                           0, SourceLocation(), 0);
+    D = RecordDecl::Create(*Context, Decl::EmptyShell());
     break;
   case pch::DECL_ENUM_CONSTANT:
     D = EnumConstantDecl::Create(*Context, 0, SourceLocation(), 0, QualType(),
@@ -1196,8 +1195,7 @@
                                             DeclarationName());
     break;
   case pch::DECL_CXX_RECORD:
-    D = CXXRecordDecl::Create(*Context, TTK_Struct, 0,
-                              SourceLocation(), 0, SourceLocation(), 0);
+    D = CXXRecordDecl::Create(*Context, Decl::EmptyShell());
     break;
   case pch::DECL_CXX_METHOD:
     D = CXXMethodDecl::Create(*Context, 0, SourceLocation(), DeclarationName(),
@@ -1227,17 +1225,18 @@
                                   DeclarationName(), 0, 0, 0);
     break;
   case pch::DECL_CLASS_TEMPLATE_SPECIALIZATION:
-    D = ClassTemplateSpecializationDecl::CreateEmpty(*Context);
+    D = ClassTemplateSpecializationDecl::Create(*Context, Decl::EmptyShell());
     break;
   case pch::DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION:
-    D = ClassTemplatePartialSpecializationDecl::CreateEmpty(*Context);
+    D = ClassTemplatePartialSpecializationDecl::Create(*Context,
+                                                            Decl::EmptyShell());
     break;
   case pch::DECL_FUNCTION_TEMPLATE:
     D = FunctionTemplateDecl::Create(*Context, 0, SourceLocation(),
                                      DeclarationName(), 0, 0);
     break;
   case pch::DECL_TEMPLATE_TYPE_PARM:
-    D = TemplateTypeParmDecl::Create(*Context, 0, SourceLocation(), 0,0,0,0,0);
+    D = TemplateTypeParmDecl::Create(*Context, Decl::EmptyShell());
     break;
   case pch::DECL_NON_TYPE_TEMPLATE_PARM:
     D = NonTypeTemplateParmDecl::Create(*Context, 0, SourceLocation(), 0,0,0,