Split AST Declaration class, in preparation for new module declaration forms.

src/ast.cc

Index: src/ast.cc
diff --git a/src/ast.cc b/src/ast.cc
index 397da5ab014505fc7d49a55fb94cd86b62291c26..a4aee4094ae0b6874e1a86f0ea669f1f3918dff4 100644
--- a/src/ast.cc
+++ b/src/ast.cc
@@ -419,7 +419,11 @@ bool CompareOperation::IsLiteralCompareNull(Expression** expr) {
 // Inlining support
 
 bool Declaration::IsInlineable() const {
-  return proxy()->var()->IsStackAllocated() && fun() == NULL;
+  return proxy()->var()->IsStackAllocated();
+}
+
+bool VariableDeclaration::IsInlineable() const {
+  return Declaration::IsInlineable() && fun() == NULL;
 }
 
 
@@ -995,7 +999,7 @@ CaseClause::CaseClause(Isolate* isolate,
     increase_node_count(); \
   }
 
-INCREASE_NODE_COUNT(Declaration)
+INCREASE_NODE_COUNT(VariableDeclaration)
 INCREASE_NODE_COUNT(Block)
 INCREASE_NODE_COUNT(ExpressionStatement)
 INCREASE_NODE_COUNT(EmptyStatement)