[m-rev.] for review: Update vim syntax to allow underscores in numeric literals.

[Julien Fischer]

Hi Peter,

On Sun, 29 Jan 2017, Peter Wang wrote:

> vim/syntax/mercury.vim:
>    Separate matches for Mercury and foreign-language numeric literals,
>    the latter matching C numeric literals.
>
>    Allow underscores in Mercury numeric literals.
>
>    Allow floats without fractional part.

That looks fine.

Julien.