[gcc r14-8145] gccrs: Add regression test for invalid label name

[Arthur Cohen]

https://gcc.gnu.org/g:119e0be8b6eea63a95c89d449c38aa133e6ad5ab

commit r14-8145-g119e0be8b6eea63a95c89d449c38aa133e6ad5ab
Author: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>
Date:   Thu Nov 9 15:45:04 2023 +0100

    gccrs: Add regression test for invalid label name
    
    An error message should be emitted when the rust code contains invalid
    label name. Add a new test for this behavior.
    
    gcc/testsuite/ChangeLog:
    
            * rust/compile/invalid_label_name.rs: New test.
    
    Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>

Diff:
---
 gcc/testsuite/rust/compile/invalid_label_name.rs | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/gcc/testsuite/rust/compile/invalid_label_name.rs b/gcc/testsuite/rust/compile/invalid_label_name.rs
new file mode 100644
index 00000000000..5c850da636c
--- /dev/null
+++ b/gcc/testsuite/rust/compile/invalid_label_name.rs
@@ -0,0 +1,23 @@
+pub fn function() {
+    'continue: loop {
+        // { dg-error "invalid label name .'continue." "" { target *-*-* } .-1 }
+        break 'extern;
+        // { dg-error "invalid label name .'extern." "" { target *-*-* } .-1 }
+    }
+
+    'break: loop {
+        // { dg-error "invalid label name .'break." "" { target *-*-* } .-1 }
+        break 'for;
+        // { dg-error "invalid label name .'for." "" { target *-*-* } .-1 }
+    }
+
+    'crate: loop {
+        // { dg-error "invalid label name .'crate." "" { target *-*-* } .-1 }
+        break 'loop;
+        // { dg-error "invalid label name .'loop." "" { target *-*-* } .-1 }
+    }
+
+    'a: loop {
+        break 'a;
+    }
+}