Fix testsuite race on additional_sources

	* testsuite/lib/target-supports.exp (check_compile): Save/restore
	additional_sources that may belong to an actual test.

From-SVN: r220807

gcc/testsuite/ChangeLog

+2015-02-19  Maxim Kuvyrkov  <maxim.kuvyrkov@linaro.org>
+
+	* testsuite/lib/target-supports.exp (check_compile): Save/restore
+	additional_sources that may belong to an actual test.
+
 2015-02-18  Jakub Jelinek  <jakub@redhat.com>
 
 	PR gcov-profile/64634

gcc/testsuite/lib/target-supports.exp

@@ -41,6 +41,12 @@ proc check_compile {basename type contents args} {
     global tool
     verbose "check_compile tool: $tool for $basename" 
 
+    # Save additional_sources to avoid compiling testsuite's sources
+    # against check_compile's source.
+    global additional_sources
+    set tmp_additional_sources "$additional_sources"
+    set additional_sources ""
+
     if { [llength $args] > 0 } {
 	set options [list "additional_flags=[lindex $args 0]"]
     } else {
@@ -86,6 +92,9 @@ proc check_compile {basename type contents args} {
 	file delete $output
     }
 
+    # Restore additional_sources.
+    set additional_sources "$tmp_additional_sources"
+
     return [list $lines $scan_output]
 }