Followup r103865 and r103915

Followup r103865 and r103915

r103915 added a parse error for 'more than 2 decimal points' in a number; this is the wrong place to check for that. Should only check whether there's more digits or identifier chars -- identifier chars would be illegal.

Added test cases for the exponent missing fails, tweaked it to be more consistent (only need to check for one e; if we have more we can lump them in with 'not digits' :)

Also cleaned up no-longer-needed suppress/restore warnings around JS parser invocation