gcc-dg.exp: Add extra options for db-final to the command line only once.

2015-08-21  Dominik Vogt  <vogt@linux.vnet.ibm.com>

	* lib/gcc-dg.exp: Add extra options for db-final to the command line
	only once.

From-SVN: r227057

gcc/testsuite/ChangeLog

+2015-08-21  Dominik Vogt  <vogt@linux.vnet.ibm.com>
+
+	* lib/gcc-dg.exp: Add extra options for db-final to the command line
+	only once.
+
 2015-08-20  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
 	* gcc.target/powerpc/altivec-35.c (foo): Add tests for vec_madd.

gcc/testsuite/lib/gcc-dg.exp

@@ -270,7 +270,7 @@ proc gcc-dg-test-1 { target_compile prog do_what extra_tool_flags } {
 	set finalcmd [lindex $x 0]
 	if { [info procs ${finalcmd}_required_options] != "" } {
 	    set req [${finalcmd}_required_options]
-	    if { $req != "" } {
+	    if { $req != "" && [lsearch -exact $extra_tool_flags $req] == -1 } {
 		lappend extra_tool_flags $req
 	    }
 	}