Fix tests for big-endian

The tests fail on s390x and presumably other big-endian systems, due
to check of raw alloc values in the MIR output.

To fix the tests remove the raw bytes from the MIR output
(via: compile-flags: -Zdump-mir-exclude-alloc-bytes) and update the
matching diffs.

tests/mir-opt/const_prop/invalid_constant.main.GVN.diff

@@ -61,17 +61,11 @@
           StorageDead(_1);
           return;
       }
-+ }
-+ 
-+ ALLOC0 (size: 4, align: 4) {
-+     00 00 00 00                                     │ ....
-+ }
-+ 
-+ ALLOC1 (size: 4, align: 4) {
-+     04 00 00 00                                     │ ....
-+ }
-+ 
-+ ALLOC2 (size: 4, align: 4) {
-+     01 00 11 00                                     │ ....
   }
++ 
++ ALLOC0 (size: 4, align: 4) { .. }
++ 
++ ALLOC1 (size: 4, align: 4) { .. }
++ 
++ ALLOC2 (size: 4, align: 4) { .. }
   

tests/mir-opt/const_prop/invalid_constant.rs

@@ -1,6 +1,6 @@
 // skip-filecheck
 //@ test-mir-pass: GVN
-//@ compile-flags: -Zmir-enable-passes=+RemoveZsts
+//@ compile-flags: -Zmir-enable-passes=+RemoveZsts -Zdump-mir-exclude-alloc-bytes
 // Verify that we can pretty print invalid constants.
 
 #![feature(adt_const_params, unsized_const_params)]

tests/mir-opt/const_prop/union.main.GVN.diff

@@ -34,9 +34,7 @@
           StorageDead(_1);
           return;
       }
-+ }
-+ 
-+ ALLOC0 (size: 4, align: 4) {
-+     01 00 00 00                                     │ ....
   }
++ 
++ ALLOC0 (size: 4, align: 4) { .. }
   

tests/mir-opt/const_prop/union.rs

@@ -1,6 +1,6 @@
 //! Tests that we can propagate into places that are projections into unions
 //@ test-mir-pass: GVN
-//@ compile-flags: -Zinline-mir
+//@ compile-flags: -Zinline-mir -Zdump-mir-exclude-alloc-bytes
 
 fn val() -> u32 {
     1

tests/mir-opt/gvn_loop.loop_deref_mut.GVN.diff

@@ -107,9 +107,7 @@
           StorageDead(_11);
           goto -> bb4;
       }
-+ }
-+ 
-+ ALLOC0 (size: 8, align: 4) {
-+     01 00 00 00 __ __ __ __                         │ ....░░░░
   }
++ 
++ ALLOC0 (size: 8, align: 4) { .. }
   

tests/mir-opt/gvn_loop.rs

@@ -1,4 +1,5 @@
 //@ test-mir-pass: GVN
+//@ compile-flags: -Zdump-mir-exclude-alloc-bytes
 
 #![crate_type = "lib"]
 #![feature(core_intrinsics, rustc_attrs)]