bless; add test for mutating a static

Author: RalfJung

src/test/ui/consts/const-eval/assign-to-static-within-other-static.stderr

@@ -2,7 +2,7 @@ error[E0080]: could not evaluate static initializer
   --> $DIR/assign-to-static-within-other-static.rs:10:5
    |
 LL |     FOO = 5;
-   |     ^^^^^^^ tried to modify a static's initial value from another static's initializer
+   |     ^^^^^^^ modifying a static's initial value from another static's initializer
 
 error: aborting due to previous error
 

src/test/ui/consts/miri_unleashed/mutable_const.stderr

@@ -11,7 +11,7 @@ LL | / const MUTATING_BEHIND_RAW: () = {
 LL | |     // Test that `MUTABLE_BEHIND_RAW` is actually immutable, by doing this at const time.
 LL | |     unsafe {
 LL | |         *MUTABLE_BEHIND_RAW = 99
-   | |         ^^^^^^^^^^^^^^^^^^^^^^^^ writing to alloc1 which is read-only
+   | |         ^^^^^^^^^^^^^^^^^^^^^^^^ modifying a static's initial value from another static's initializer
 LL | |     }
 LL | | };
    | |__-

src/test/ui/consts/miri_unleashed/mutating_global.rs

@@ -0,0 +1,15 @@
+// compile-flags: -Zunleash-the-miri-inside-of-you
+
+// Make sure we cannot mutate globals.
+
+static mut GLOBAL: i32 = 0;
+
+const MUTATING_GLOBAL: () = {
+    unsafe {
+        GLOBAL = 99 //~ ERROR any use of this value will cause an error
+        //~^ WARN skipping const checks
+        //~| WARN skipping const checks
+    }
+};
+
+fn main() {}

src/test/ui/consts/miri_unleashed/mutating_global.stderr

@@ -0,0 +1,29 @@
+warning: skipping const checks
+  --> $DIR/mutating_global.rs:9:9
+   |
+LL |         GLOBAL = 99
+   |         ^^^^^^
+
+warning: skipping const checks
+  --> $DIR/mutating_global.rs:9:9
+   |
+LL |         GLOBAL = 99
+   |         ^^^^^^
+
+error: any use of this value will cause an error
+  --> $DIR/mutating_global.rs:9:9
+   |
+LL | / const MUTATING_GLOBAL: () = {
+LL | |     unsafe {
+LL | |         GLOBAL = 99
+   | |         ^^^^^^^^^^^ modifying a static's initial value from another static's initializer
+LL | |
+LL | |
+LL | |     }
+LL | | };
+   | |__-
+   |
+   = note: `#[deny(const_err)]` on by default
+
+error: aborting due to previous error
+

src/test/ui/consts/static_mut_containing_mut_ref2.mut_refs.stderr

@@ -2,7 +2,7 @@ error[E0080]: could not evaluate static initializer
   --> $DIR/static_mut_containing_mut_ref2.rs:7:45
    |
 LL | pub static mut STDERR_BUFFER: () = unsafe { *(&mut STDERR_BUFFER_SPACE) = 42; };
-   |                                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ tried to modify a static's initial value from another static's initializer
+   |                                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ modifying a static's initial value from another static's initializer
 
 error: aborting due to previous error
 

src/test/ui/consts/static_mut_containing_mut_ref3.stderr

@@ -2,7 +2,7 @@ error[E0080]: could not evaluate static initializer
   --> $DIR/static_mut_containing_mut_ref3.rs:3:31
    |
 LL | static mut BAR: () = unsafe { FOO.0 = 99; };
-   |                               ^^^^^^^^^^ tried to modify a static's initial value from another static's initializer
+   |                               ^^^^^^^^^^ modifying a static's initial value from another static's initializer
 
 error: aborting due to previous error