mbe: Restructure macro_metavar_expr tests

These tests have expanded beyond the RFC, so rename the directory
`rfc-3086-metavar-expr` to `metavar-expressions`. `concat` (which wasn't
part of the RFC) now fits in this group, so merge its tests into the
`metavar-expressions` directory.

Additionally rename some related `issue-*` tests.

Author: tgross35

src/tools/tidy/src/issues.txt

@@ -2849,7 +2849,6 @@ ui/macros/issue-98466.rs
 ui/macros/issue-99261.rs
 ui/macros/issue-99265.rs
 ui/macros/issue-99907.rs
-ui/macros/rfc-3086-metavar-expr/issue-111904.rs
 ui/malformed/issue-107423-unused-delim-only-one-no-pair.rs
 ui/malformed/issue-69341-malformed-derive-inert.rs
 ui/marker_trait_attr/issue-61651-type-mismatch.rs

tests/ui/macros/macro-metavar-expr-concat/allowed-operations.rs renamed to tests/ui/macros/metavar-expressions/concat-allowed-operations.rs

@@ -1,5 +1,5 @@
 error[E0425]: cannot find value `abcdef` in this scope
-  --> $DIR/hygiene.rs:5:10
+  --> $DIR/concat-hygiene.rs:5:10
    |
 LL |         ${concat($lhs, $rhs)}
    |          ^^^^^^^^^^^^^^^^^^^^ not found in this scope

tests/ui/macros/macro-metavar-expr-concat/hygiene.rs renamed to tests/ui/macros/metavar-expressions/concat-hygiene.rs

@@ -1,87 +1,87 @@
 error: expected identifier or string literal
-  --> $DIR/raw-identifiers.rs:28:22
+  --> $DIR/concat-raw-identifiers.rs:28:22
    |
 LL |         let ${concat(r#abc, abc)}: () = ();
    |                      ^^^^^
 
 error: expected identifier or string literal
-  --> $DIR/raw-identifiers.rs:32:27
+  --> $DIR/concat-raw-identifiers.rs:32:27
    |
 LL |         let ${concat(abc, r#abc)}: () = ();
    |                           ^^^^^
 
 error: expected identifier or string literal
-  --> $DIR/raw-identifiers.rs:35:22
+  --> $DIR/concat-raw-identifiers.rs:35:22
    |
 LL |         let ${concat(r#abc, r#abc)}: () = ();
    |                      ^^^^^
 
 error: `${concat(..)}` currently does not support raw identifiers
-  --> $DIR/raw-identifiers.rs:5:28
+  --> $DIR/concat-raw-identifiers.rs:5:28
    |
 LL |         let ${concat(abc, $rhs)}: () = ();
    |                            ^^^
 
 error: `${concat(..)}` currently does not support raw identifiers
-  --> $DIR/raw-identifiers.rs:12:23
+  --> $DIR/concat-raw-identifiers.rs:12:23
    |
 LL |         let ${concat($lhs, abc)}: () = ();
    |                       ^^^
 
 error: `${concat(..)}` currently does not support raw identifiers
-  --> $DIR/raw-identifiers.rs:19:23
+  --> $DIR/concat-raw-identifiers.rs:19:23
    |
 LL |         let ${concat($lhs, $rhs)}: () = ();
    |                       ^^^
 
 error: `${concat(..)}` currently does not support raw identifiers
-  --> $DIR/raw-identifiers.rs:19:29
+  --> $DIR/concat-raw-identifiers.rs:19:29
    |
 LL |         let ${concat($lhs, $rhs)}: () = ();
    |                             ^^^
 
 error: `${concat(..)}` currently does not support raw identifiers
-  --> $DIR/raw-identifiers.rs:19:23
+  --> $DIR/concat-raw-identifiers.rs:19:23
    |
 LL |         let ${concat($lhs, $rhs)}: () = ();
    |                       ^^^
    |
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error: `${concat(..)}` currently does not support raw identifiers
-  --> $DIR/raw-identifiers.rs:42:28
+  --> $DIR/concat-raw-identifiers.rs:42:28
    |
 LL |         let ${concat(abc, $rhs)}: () = ();
    |                            ^^^
 
 error: `${concat(..)}` currently does not support raw identifiers
-  --> $DIR/raw-identifiers.rs:49:23
+  --> $DIR/concat-raw-identifiers.rs:49:23
    |
 LL |         let ${concat($lhs, abc)}: () = ();
    |                       ^^^
 
 error: `${concat(..)}` currently does not support raw identifiers
-  --> $DIR/raw-identifiers.rs:56:23
+  --> $DIR/concat-raw-identifiers.rs:56:23
    |
 LL |         let ${concat($lhs, $rhs)}: () = ();
    |                       ^^^
 
 error: `${concat(..)}` currently does not support raw identifiers
-  --> $DIR/raw-identifiers.rs:56:29
+  --> $DIR/concat-raw-identifiers.rs:56:29
    |
 LL |         let ${concat($lhs, $rhs)}: () = ();
    |                             ^^^
 
 error: `${concat(..)}` currently does not support raw identifiers
-  --> $DIR/raw-identifiers.rs:56:23
+  --> $DIR/concat-raw-identifiers.rs:56:23
    |
 LL |         let ${concat($lhs, $rhs)}: () = ();
    |                       ^^^
    |
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error: expected pattern, found `$`
-  --> $DIR/raw-identifiers.rs:28:13
+  --> $DIR/concat-raw-identifiers.rs:28:13
    |
 LL |         let ${concat(r#abc, abc)}: () = ();
    |             ^ expected pattern

tests/ui/macros/macro-metavar-expr-concat/hygiene.stderr renamed to tests/ui/macros/metavar-expressions/concat-hygiene.stderr

@@ -1,17 +1,17 @@
 error: invalid syntax
-  --> $DIR/repetitions.rs:14:20
+  --> $DIR/concat-repetitions.rs:14:20
    |
 LL |             const ${concat($a, Z)}: i32 = 3;
    |                    ^^^^^^^^^^^^^^^
 
 error: invalid syntax
-  --> $DIR/repetitions.rs:22:17
+  --> $DIR/concat-repetitions.rs:22:17
    |
 LL |         read::<${concat($t, $en)}>()
    |                 ^^^^^^^^^^^^^^^^^
 
 error: invalid syntax
-  --> $DIR/repetitions.rs:22:17
+  --> $DIR/concat-repetitions.rs:22:17
    |
 LL |         read::<${concat($t, $en)}>()
    |                 ^^^^^^^^^^^^^^^^^