Auto merge of #1992 - RalfJung:sdiv, r=RalfJung

adjust for div/rem overflow being UB

This is the Miri side of rust-lang/rust#94512. Just some error messages change.

Author: bors

rust-version

@@ -1 +1 @@
-f0c4da49983aa699f715caf681e3154b445fb60b
+45660949132222ba7ec0905649b2affd68e0e13c

tests/compile-fail/intrinsics/exact_div4.rs

@@ -1,5 +1,5 @@
 #![feature(core_intrinsics)]
 fn main() {
     // divison of MIN by -1
-    unsafe { std::intrinsics::exact_div(i64::MIN, -1); } //~ ERROR result of dividing MIN by -1 cannot be represented
+    unsafe { std::intrinsics::exact_div(i64::MIN, -1); } //~ ERROR overflow in signed remainder (dividing MIN by -1)
 }

tests/compile-fail/intrinsics/simd-div-overflow.rs

@@ -0,0 +1,15 @@
+#![feature(platform_intrinsics, repr_simd)]
+
+extern "platform-intrinsic" {
+    pub(crate) fn simd_div<T>(x: T, y: T) -> T;
+}
+
+#[repr(simd)]
+#[allow(non_camel_case_types)]
+struct i32x2(i32, i32);
+
+fn main() { unsafe {
+    let x = i32x2(1, i32::MIN);
+    let y = i32x2(1, -1);
+    simd_div(x, y); //~ERROR Undefined Behavior: overflow in signed division
+} }

tests/compile-fail/intrinsics/unchecked_div1.rs

@@ -1,5 +1,5 @@
 #![feature(core_intrinsics)]
 fn main() {
     // MIN/-1 cannot be represented
-    unsafe { std::intrinsics::unchecked_div(i16::MIN, -1); } //~ ERROR overflow executing `unchecked_div`
+    unsafe { std::intrinsics::unchecked_div(i16::MIN, -1); } //~ ERROR overflow in signed division (dividing MIN by -1)
 }

tests/run-pass/integer-ops.rs

@@ -116,6 +116,9 @@ pub fn main() {
     assert_eq!(100i8.wrapping_rem(10), 0);
     assert_eq!((-128i8).wrapping_rem(-1), 0);
 
+    assert_eq!(i32::MIN.wrapping_div(-1), i32::MIN);
+    assert_eq!(i32::MIN.wrapping_rem(-1), 0);
+
     assert_eq!(100i8.wrapping_neg(), -100);
     assert_eq!((-128i8).wrapping_neg(), -128);