fixup! gdb/testsuite: replace hipcc with amdclang++ as the HIP compiler

Author: spatrang

gdb/testsuite/lib/gdb.exp

@@ -6440,6 +6440,18 @@ proc gdb_compile {source dest type options} {
     global objdir
     global gdb_saved_set_unbuffered_mode_obj
 
+    # hipcc's --genco (generate a standalone device code object) has
+    # no direct amdclang++ spelling; the equivalent is
+    # --cuda-device-only.  Translate it here, before the options are
+    # processed, so testcases can keep using the portable --genco.
+    if {[lsearch -exact $options hip] != -1} {
+	set genco_idx [lsearch -exact $options "additional_flags=--genco"]
+	if {$genco_idx != -1} {
+	    set options [lreplace $options $genco_idx $genco_idx \
+			     "additional_flags=--cuda-device-only"]
+	}
+    }
+
     if {[lsearch -exact $options hip] != -1
 	&& [istarget "*-*-mingw*"]} {
 	# target_compile by default links with -lm, if the target