Provisional implementation of stack allocated catch variables.

src/ast-inl.h

Index: src/ast-inl.h
diff --git a/src/ast-inl.h b/src/ast-inl.h
index c750e6b03c383cd87ea1de45a83bd9911f534057..ba395f1c7832fcc6fc52ca2432fec88d9feb8620 100644
--- a/src/ast-inl.h
+++ b/src/ast-inl.h
@@ -50,7 +50,9 @@ Block::Block(Isolate* isolate,
              bool is_initializer_block)
     : BreakableStatement(isolate, labels, TARGET_FOR_NAMED_ONLY),
       statements_(capacity),
-      is_initializer_block_(is_initializer_block) {
+      is_initializer_block_(is_initializer_block),
+      source_beg_statement_pos_(-1),
+      source_end_statement_pos_(-1) {
 }