Built-in Natural literals in Core

Add support for built-in Natural literals in Core.

- Replace MachInt,MachWord, LitInteger, etc. with a single LitNumber
  constructor with a LitNumType field
- Support built-in Natural literals
- Add desugar warning for negative literals
- Move Maybe(..) from GHC.Base to GHC.Maybe for module dependency
  reasons

This patch introduces only a few rules for Natural literals (compared
to Integer's rules). Factorization of the built-in rules for numeric
literals will be done in another patch as this one is already big to
review.

Test Plan:
  validate
  test build with integer-simple

Reviewers: hvr, bgamari, goldfire, Bodigrim, simonmar

Reviewed By: bgamari

Subscribers: phadej, simonpj, RyanGlScott, carter, hsyl20, rwbarton,
thomie

GHC Trac Issues: #14170, #14465

Differential Revision: https://phabricator.haskell.org/D4212

1 files changed, 1 insertions, 1 deletions

diff --git a/testsuite/tests/partial-sigs/should_fail/T10999.stderr b/testsuite/tests/partial-sigs/should_fail/T10999.stderr
index 88652a7831..5da96928c4 100644
--- a/testsuite/tests/partial-sigs/should_fail/T10999.stderr
+++ b/testsuite/tests/partial-sigs/should_fail/T10999.stderr
@@ -25,7 +25,7 @@ T10999.hs:8:28: error:
         instance Ord Ordering -- Defined in ‘GHC.Classes’
         instance Ord Integer
           -- Defined in ‘integer-gmp-1.0.1.0:GHC.Integer.Type’
-        ...plus 23 others
+        ...plus 22 others
         ...plus three instances involving out-of-scope types
         (use -fprint-potential-instances to see them all)
     • In the second argument of ‘($)’, namely ‘f ()’