Bless mir opt tests and remove some broken custom MIR

Author: oli-obk

tests/mir-opt/dataflow-const-prop/enum.rs

@@ -62,7 +62,7 @@ fn statics() {
 
     static RC: &E = &E::V2(4);
 
-    // CHECK: [[t:_.*]] = const {alloc2: &&E};
+    // CHECK: [[t:_.*]] = const {alloc4: &&E};
     // CHECK: [[e2]] = (*[[t]]);
     let e2 = RC;
 

tests/mir-opt/instsimplify/combine_transmutes.integer_transmutes.InstSimplify.diff

@@ -5,19 +5,15 @@
       let mut _0: ();
       let mut _1: u32;
       let mut _2: i64;
-      let mut _3: i64;
-      let mut _4: u32;
-      let mut _5: usize;
+      let mut _3: usize;
 
       bb0: {
 -         _1 = const 1_i32 as u32 (Transmute);
+-         _2 = const 1_u64 as i64 (Transmute);
+-         _3 = const 1_isize as usize (Transmute);
 +         _1 = const 1_i32 as u32 (IntToInt);
-          _2 = const 1_i32 as i64 (Transmute);
--         _3 = const 1_u64 as i64 (Transmute);
-+         _3 = const 1_u64 as i64 (IntToInt);
-          _4 = const 1_u64 as u32 (Transmute);
--         _5 = const 1_isize as usize (Transmute);
-+         _5 = const 1_isize as usize (IntToInt);
++         _2 = const 1_u64 as i64 (IntToInt);
++         _3 = const 1_isize as usize (IntToInt);
           return;
       }
   }

tests/mir-opt/instsimplify/combine_transmutes.rs

@@ -6,7 +6,7 @@
 #![feature(custom_mir)]
 
 use std::intrinsics::mir::*;
-use std::mem::{MaybeUninit, ManuallyDrop, transmute};
+use std::mem::{transmute, ManuallyDrop, MaybeUninit};
 
 // EMIT_MIR combine_transmutes.identity_transmutes.InstSimplify.diff
 pub unsafe fn identity_transmutes() {
@@ -25,19 +25,15 @@ pub unsafe fn integer_transmutes() {
     // CHECK-LABEL: fn integer_transmutes(
     // CHECK-NOT: _i32 as u32 (Transmute);
     // CHECK: _i32 as u32 (IntToInt);
-    // CHECK: _i32 as i64 (Transmute);
     // CHECK-NOT: _u64 as i64 (Transmute);
     // CHECK: _u64 as i64 (IntToInt);
-    // CHECK: _u64 as u32 (Transmute);
     // CHECK-NOT: _isize as usize (Transmute);
     // CHECK: _isize as usize (IntToInt);
 
     mir! {
         {
             let A = CastTransmute::<i32, u32>(1); // Can be a cast
-            let B = CastTransmute::<i32, i64>(1); // UB
             let C = CastTransmute::<u64, i64>(1); // Can be a cast
-            let D = CastTransmute::<u64, u32>(1); // UB
             let E = CastTransmute::<isize, usize>(1); // Can be a cast
             Return()
         }
@@ -62,4 +58,7 @@ pub unsafe fn adt_transmutes() {
     let _a: ManuallyDrop<String> = transmute(MaybeUninit::<String>::uninit());
 }
 
-pub union Union32 { u32: u32, i32: i32 }
+pub union Union32 {
+    u32: u32,
+    i32: i32,
+}