[pushed] [gdb/testsuite] Fix gdb.dap/corefile.exp with Tcl 9.0

[Tom de Vries <tdevries@suse.de>]

With test-case gdb.dap/corefile.exp and Tcl 9.0 I run into:
...
ERROR: tcl error sourcing gdb/testsuite/gdb.dap/corefile.exp.
ERROR: tcl error code TCL LOOKUP VARNAME reg_name
ERROR: can't read "reg_name": no such variable
    while executing
"s \$$reg_name"
    (in namespace eval "::ton::2json" script line 1)
    invoked from within
"namespace eval ton::2json $obj"
...

Fix this by making clear that reg_name is a variable in the global namespace.

Likewise for variable new_value.

Tested on aarch64-linux.
---
 gdb/testsuite/gdb.dap/corefile.exp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/testsuite/gdb.dap/corefile.exp b/gdb/testsuite/gdb.dap/corefile.exp
index 088cc82d4c8..256edcfb6fe 100644
--- a/gdb/testsuite/gdb.dap/corefile.exp
+++ b/gdb/testsuite/gdb.dap/corefile.exp
@@ -97,7 +97,7 @@ set expected_exception_count 1
 if {[string is integer -strict $reg_value]} {
     set new_value [expr {$reg_value + 1}]
     set obj [dap_request_and_response setExpression \
-		 {o expression [s \$$reg_name] value [s $new_value]}]
+		 {o expression [s \$$::reg_name] value [s $::new_value]}]
     set response [lindex $obj 0]
     gdb_assert { [dict get $response success] == "false" } \
 	"set register fails"

base-commit: 9c16e272180d38bcdc9ab11e812102db8b88a87e
-- 
2.51.0