Missing var declaration for tmp created by JsStackEmulator

Detected by running Closure Compiler on GWT output.

Change-Id: I36c9cf402a94cde392b701c34192b1df051263f7

dev/core/src/com/google/gwt/dev/js/JsStackEmulator.java

diff --git a/dev/core/src/com/google/gwt/dev/js/JsStackEmulator.java b/dev/core/src/com/google/gwt/dev/js/JsStackEmulator.java
index 44c917d..e716f9d 100644
--- a/dev/core/src/com/google/gwt/dev/js/JsStackEmulator.java
+++ b/dev/core/src/com/google/gwt/dev/js/JsStackEmulator.java
@@ -1043,6 +1043,7 @@
     stackDepthVar.setInitExpr(new JsNumberLiteral(info, (-1)));
     JsVar lineNumbersVar = new JsVar(info, lineNumbers);
     lineNumbersVar.setInitExpr(new JsArrayLiteral(info));
+    JsVar tmpVar = new JsVar(info,tmp);
 
     JsVars vars;
     JsStatement first = jsProgram.getGlobalBlock().getStatements().get(0);
@@ -1055,5 +1056,6 @@
     vars.add(stackVar);
     vars.add(stackDepthVar);
     vars.add(lineNumbersVar);
+    vars.add(tmpVar);
   }
 }