const-eval error: always say in which item the error occurred

RalfJung · RalfJung · commit 1b5ef5caebc8 · 2025-06-07T13:42:30.000+02:00
also adjust the wording a little so that we don't say "the error occurred here" for two different spans
diff --git a/tests/fail/const-ub-checks.stderr b/tests/fail/const-ub-checks.stderr
@@ -2,7 +2,7 @@ error[E0080]: accessing memory based on pointer with alignment ALIGN, but alignm
   --> tests/fail/const-ub-checks.rs:LL:CC
    |
 LL |     ptr.read();
-   |     ^^^^^^^^^^ evaluation of constant value failed here
+   |     ^^^^^^^^^^ evaluation of `UNALIGNED_READ` failed here
 
 note: erroneous constant encountered
   --> tests/fail/const-ub-checks.rs:LL:CC
diff --git a/tests/fail/erroneous_const2.stderr b/tests/fail/erroneous_const2.stderr
@@ -2,7 +2,7 @@ error[E0080]: attempt to compute `5_u32 - 6_u32`, which would overflow
   --> tests/fail/erroneous_const2.rs:LL:CC
    |
 LL | const FOO: u32 = [X - Y, Y - X][(X < Y) as usize];
-   |                   ^^^^^ evaluation of constant value failed here
+   |                   ^^^^^ evaluation of `FOO` failed here
 
 note: erroneous constant encountered
   --> tests/fail/erroneous_const2.rs:LL:CC

Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,7 @@ error[E0080]: accessing memory based on pointer with alignment ALIGN, but alignm`
`2`	`2`	`--> tests/fail/const-ub-checks.rs:LL:CC`
`3`	`3`	`\|`
`4`	`4`	`LL \| ptr.read();`
`5`		`- \| ^^^^^^^^^^ evaluation of constant value failed here`
	`5`	+ \| ^^^^^^^^^^ evaluation of `UNALIGNED_READ` failed here
`6`	`6`
`7`	`7`	`note: erroneous constant encountered`
`8`	`8`	`--> tests/fail/const-ub-checks.rs:LL:CC`
Original file line number	Diff line number	Diff line change
@@ -2,7 +2,7 @@ error[E0080]: attempt to compute `5_u32 - 6_u32`, which would overflow
`2`	`2`	`--> tests/fail/erroneous_const2.rs:LL:CC`
`3`	`3`	`\|`
`4`	`4`	`LL \| const FOO: u32 = [X - Y, Y - X][(X < Y) as usize];`
`5`		`- \| ^^^^^ evaluation of constant value failed here`
	`5`	+ \| ^^^^^ evaluation of `FOO` failed here
`6`	`6`
`7`	`7`	`note: erroneous constant encountered`
`8`	`8`	`--> tests/fail/erroneous_const2.rs:LL:CC`