Add proper support for "use asm"; blocks. Disable -c optimization within "use asm"; sections and preserve floating point literals in their original form. Non-asm.js sections are optimized as before. Asm.js sections can still be mangled and minified of whitespace. No special command line flags are required.

lib/scope.js

@@ -119,6 +119,10 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
             push_uniq(scope.directives, node.value);
             return true;
         }
+        if (node instanceof AST_Number) {
+            node.scope = scope;
+            return true;
+        }
         if (node instanceof AST_With) {
             for (var s = scope; s; s = s.parent_scope)
                 s.uses_with = true;