Update syntax for numeric literals This is an exact pattern match version.
Update syntax for numeric literals
This is an exact pattern match version.

* Modify syntax for HexFloatLiterals extension [1]
* Modify syntax for BinaryLiterals extension [2]
* Modify syntax for NumericUnderscores extension [3] [4]

I visually verified this patch with the these files [5] [6].

[1]: https://ghc.haskell.org/trac/ghc/ticket/9224
[2]: https://ghc.haskell.org/trac/ghc/ticket/13126
[3]: https://ghc.haskell.org/trac/ghc/ticket/14473
[4]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0009-numeric-underscores.rst
[5]: https://github.com/takenobu-hs/ghc/blob/squashed-numeric-underscores/testsuite/tests/parser/should_run/NumericUnderscores0.hs
[6]: https://github.com/takenobu-hs/ghc/blob/squashed-numeric-underscores/testsuite/tests/parser/should_run/NumericUnderscores1.hs

JustusAdam/language-haskell,JustusAdam/language-haskell