Fixes missing overflow lint for i64 #14269

The `type_overflow` lint, doesn't catch the overflow for `i64` because
the overflow happens earlier in the parse phase when the `u64` as biggest
possible int gets casted to `i64` , without checking the for overflows.
We can't lint in the parse phase, so a refactoring of the `LitInt` type
was necessary.

The types `LitInt`, `LitUint` and `LitIntUnsuffixed` where merged to one
type `LitInt` which stores it's value as `u64`. An additional parameter was
added which indicate the signedness of the type and the sign of the value.

1 files changed, 19 insertions, 9 deletions

diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 675588a4460..095dca66164 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -2415,15 +2415,25 @@ impl<'a> State<'a> {
                 word(&mut self.s, res.as_slice())
             }
             ast::LitInt(i, t) => {
-                word(&mut self.s,
-                     ast_util::int_ty_to_string(t, Some(i)).as_slice())
-            }
-            ast::LitUint(u, t) => {
-                word(&mut self.s,
-                     ast_util::uint_ty_to_string(t, Some(u)).as_slice())
-            }
-            ast::LitIntUnsuffixed(i) => {
-                word(&mut self.s, format!("{}", i).as_slice())
+                match t {
+                    ast::SignedIntLit(st, ast::Plus) => {
+                        word(&mut self.s,
+                             ast_util::int_ty_to_string(st, Some(i as i64)).as_slice())
+                    }
+                    ast::SignedIntLit(st, ast::Minus) => {
+                        word(&mut self.s,
+                             ast_util::int_ty_to_string(st, Some(-(i as i64))).as_slice())
+                    }
+                    ast::UnsignedIntLit(ut) => {
+                        word(&mut self.s, ast_util::uint_ty_to_string(ut, Some(i)).as_slice())
+                    }
+                    ast::UnsuffixedIntLit(ast::Plus) => {
+                        word(&mut self.s, format!("{}", i).as_slice())
+                    }
+                    ast::UnsuffixedIntLit(ast::Minus) => {
+                        word(&mut self.s, format!("-{}", i).as_slice())
+                    }
+                }
             }
             ast::LitFloat(ref f, t) => {
                 word(&mut self.s,