Fix handling of "use asm" when no command line flags are passed to uglifyjs. SCOPE_IS_NEEDED is unconditionally true now. Refactored floating point literal parsing to be more in keeping with the AST class design.

lib/ast.js

@@ -864,10 +864,11 @@ var AST_String = DEFNODE("String", "value quote", {
     }
 }, AST_Constant);
 
-var AST_Number = DEFNODE("Number", "value", {
+var AST_Number = DEFNODE("Number", "value literal", {
     $documentation: "A number literal",
     $propdoc: {
-        value: "[number] the numeric value"
+        value: "[number] the numeric value",
+        literal: "[string] numeric value as string (optional)"
     }
 }, AST_Constant);