Don't force DWARF4 for AutoFDO tests

Support for DWARF5 was added to create_gcov in
https://github.com/google/autofdo so we no longer need
to force DWARF4 for AutoFDO tests.

Tested on x86_64-pc-linux-gnu.

gcc/testsuite/ChangeLog:
	* lib/profopt.exp: Don't force DWARF4 for AutoFDO tests

gcc/testsuite/lib/profopt.exp

@@ -289,7 +289,7 @@ proc auto-profopt-execute { src } {
         return
     }
     set profile_wrapper [profopt-perf-wrapper]
-    set profile_option "-gdwarf-4 -DFOR_AUTOFDO_TESTING"
+    set profile_option "-g -DFOR_AUTOFDO_TESTING"
     set feedback_option "-fauto-profile -DFOR_AUTOFDO_TESTING -fearly-inlining"
     set run_autofdo 1
     profopt-execute $src