Rollup merge of rust-lang#68937 - ecstatic-morse:unchecked-intrinsics…

…-test, r=RalfJung

Test failure of unchecked arithmetic intrinsics in const eval

Test that the unchecked arithmetic intrinsics that were made unstably const in rust-lang#68809 emit an error during const-eval if given invalid input.

Addresses [this comment](rust-lang#68809 (comment)).

r? @RalfJung

src/test/ui/consts/const-int-unchecked.rs

@@ -1,4 +1,5 @@
 #![feature(core_intrinsics)]
+#![feature(const_int_unchecked_arith)]
 
 use std::intrinsics;
 
@@ -117,4 +118,25 @@ const SHR_I64_NEG_RANDOM: i64 = unsafe { intrinsics::unchecked_shr(5_i64, -30) }
 const SHR_I128_NEG_RANDOM: i128 = unsafe { intrinsics::unchecked_shr(5_i128, -93) };
 //~^ ERROR any use of this value will cause an error
 
+// Other arithmetic functions:
+
+const _: u16 = unsafe { std::intrinsics::unchecked_add(40000u16, 30000) };
+//~^ ERROR any use of this value will cause an error
+
+const _: u32 = unsafe { std::intrinsics::unchecked_sub(14u32, 22) };
+//~^ ERROR any use of this value will cause an error
+
+const _: u16 = unsafe { std::intrinsics::unchecked_mul(300u16, 250u16) };
+//~^ ERROR any use of this value will cause an error
+
+const _: i32 = unsafe { std::intrinsics::unchecked_div(1, 0) };
+//~^ ERROR any use of this value will cause an error
+const _: i32 = unsafe { std::intrinsics::unchecked_div(i32::min_value(), -1) };
+//~^ ERROR any use of this value will cause an error
+
+const _: i32 = unsafe { std::intrinsics::unchecked_rem(1, 0) };
+//~^ ERROR any use of this value will cause an error
+const _: i32 = unsafe { std::intrinsics::unchecked_rem(i32::min_value(), -1) };
+//~^ ERROR any use of this value will cause an error
+
 fn main() {}