[AST/Parser] Convert TypeLoc struct into aligned class

include/swift/AST/ASTNode.h

@@ -30,7 +30,7 @@ namespace swift {
   class Stmt;
   class Decl;
   class Pattern;
-  struct TypeLoc;
+  class TypeLoc;
   class DeclContext;
   class SourceLoc;
   class SourceRange;

include/swift/AST/ASTPrinter.h

@@ -30,7 +30,7 @@ namespace swift {
   class TypeDecl;
   class EnumElementDecl;
   class Type;
-  struct TypeLoc;
+  class TypeLoc;
   class Pattern;
   class ExtensionDecl;
   class NominalTypeDecl;

include/swift/AST/ASTWalker.h

@@ -25,7 +25,7 @@ class ModuleDecl;
 class Stmt;
 class Pattern;
 class TypeRepr;
-struct TypeLoc;
+class TypeLoc;
 class ParameterList;
 enum class AccessKind: unsigned char;
 

include/swift/AST/TypeAlignments.h

@@ -51,6 +51,7 @@ namespace swift {
   class TypeVariableType;
   class TypeBase;
   class TypeDecl;
+  class TypeLoc;
   class ValueDecl;
 
   /// We frequently use three tag bits on all of these types.
@@ -63,6 +64,7 @@ namespace swift {
   constexpr size_t PatternAlignInBits = 3;
   constexpr size_t SILFunctionAlignInBits = 2;
   constexpr size_t TypeVariableAlignInBits = 4;
+  constexpr size_t TypeLocAlignInBits = 3;
 }
 
 namespace llvm {
@@ -124,6 +126,8 @@ LLVM_DECLARE_TYPE_ALIGNMENT(swift::SILFunction,
 
 LLVM_DECLARE_TYPE_ALIGNMENT(swift::AttributeBase, swift::AttrAlignInBits)
 
+LLVM_DECLARE_TYPE_ALIGNMENT(swift::TypeLoc, swift::TypeLocAlignInBits)
+
 static_assert(alignof(void*) >= 2, "pointer alignment is too small");
 
 #endif

include/swift/AST/TypeCheckRequests.h

@@ -48,7 +48,7 @@ class RequirementRepr;
 class SpecializeAttr;
 class TrailingWhereClause;
 class TypeAliasDecl;
-struct TypeLoc;
+class TypeLoc;
 class Witness;
 struct TypeWitnessAndDecl;
 class ValueDecl;

include/swift/AST/TypeLoc.h

@@ -19,6 +19,7 @@
 
 #include "swift/Basic/SourceLoc.h"
 #include "swift/AST/Type.h"
+#include "swift/AST/TypeAlignments.h"
 #include "llvm/ADT/PointerIntPair.h"
 
 namespace swift {
@@ -28,8 +29,7 @@ class TypeRepr;
 
 /// TypeLoc - Provides source location information for a parsed type.
 /// A TypeLoc is stored in AST nodes which use an explicitly written type.
-struct TypeLoc {
-private:
+class alignas(1 << TypeLocAlignInBits) TypeLoc {
   Type Ty;
   TypeRepr *TyR = nullptr;
 

include/swift/Parse/Parser.h

@@ -54,7 +54,7 @@ namespace swift {
   class ScopeInfo;
   class SourceManager;
   class TupleType;
-  struct TypeLoc;
+  class TypeLoc;
   
   struct EnumElementInfo;
   

include/swift/Subsystems.h

@@ -67,7 +67,7 @@ namespace swift {
   class Token;
   class TopLevelContext;
   class TypeCheckerOptions;
-  struct TypeLoc;
+  class TypeLoc;
   class UnifiedStatsReporter;
 
   namespace Lowering {

lib/Sema/ConstraintLocator.h

@@ -35,7 +35,7 @@
 namespace swift {
 
 class Expr;
-struct TypeLoc;
+class TypeLoc;
 class VarDecl;
 class Pattern;
 class SourceManager;