[gdb/testsuite] Minimize gdb restarts

Minimize gdb restarts, applying the following rules:
- don't use prepare_for_testing unless necessary
- don't use clean_restart unless necessary

Also, if possible, replace build_for_executable + clean_restart
with prepare_for_testing for brevity.

Touches 68 test-cases.

Tested on x86_64-linux.

1 files changed, 1 insertions, 1 deletions

diff --git a/gdb/testsuite/gdb.gdb/unittest.exp b/gdb/testsuite/gdb.gdb/unittest.exp
index 3622243..670205f 100644
--- a/gdb/testsuite/gdb.gdb/unittest.exp
+++ b/gdb/testsuite/gdb.gdb/unittest.exp
@@ -24,7 +24,7 @@ set do_xml_test [expr ![gdb_skip_xml_test]]
 
 standard_testfile
 
-if {[prepare_for_testing "failed to prepare" $testfile $srcfile debug]} {
+if {[build_executable "failed to prepare" $testfile $srcfile debug]} {
     return -1
 }