Auto merge of #50912 - varkor:exhaustive-integer-matching, r=arielb1

Exhaustive integer matching

This adds a new feature flag `exhaustive_integer_patterns` that enables exhaustive matching of integer types by their values. For example, the following is now accepted:
```rust
#![feature(exhaustive_integer_patterns)]
#![feature(exclusive_range_pattern)]

fn matcher(x: u8) {
  match x { // ok
    0 .. 32 => { /* foo */ }
    32 => { /* bar */ }
    33 ..= 255 => { /* baz */ }
  }
}
```
This matching is permitted on all integer (signed/unsigned and char) types. Sensible error messages are also provided. For example:
```rust
fn matcher(x: u8) {
  match x { //~ ERROR
    0 .. 32 => { /* foo */ }
  }
}
```
results in:
```
error[E0004]: non-exhaustive patterns: `32u8...255u8` not covered
 --> matches.rs:3:9
  |
6 |   match x {
  |         ^ pattern `32u8...255u8` not covered
```

This implements https://github.com/rust-lang/rfcs/issues/1550 for https://github.com/rust-lang/rust/issues/50907. While there hasn't been a full RFC for this feature, it was suggested that this might be a feature that obviously complements the existing exhaustiveness checks (e.g. for `bool`) and so a feature gate would be sufficient for now.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/librustc/mir/mod.rs b/src/librustc/mir/mod.rs
index 54fe30e609d..bafeb5dd128 100644
--- a/src/librustc/mir/mod.rs
+++ b/src/librustc/mir/mod.rs
@@ -2228,7 +2228,7 @@ pub fn fmt_const_val<W: Write>(fmt: &mut W, const_val: &ty::Const) -> fmt::Resul
     }
 }
 
-pub fn print_miri_value<W: Write>(value: Value, ty: Ty, f: &mut W) -> fmt::Result {
+pub fn print_miri_value<'tcx, W: Write>(value: Value, ty: Ty<'tcx>, f: &mut W) -> fmt::Result {
     use ty::TypeVariants::*;
     // print some primitives
     if let Value::Scalar(ScalarMaybeUndef::Scalar(Scalar::Bits { bits, .. })) = value {