Improve comments on check_v3_target_filesystem_ts

	* testsuite/lib/libstdc++.exp (check_v3_target_filesystem_ts): Improve
	comments.

From-SVN: r238995

libstdc++-v3/ChangeLog

 2016-08-02  Jonathan Wakely  <jwakely@redhat.com>
 
+	* testsuite/lib/libstdc++.exp (check_v3_target_filesystem_ts): Improve
+	comments.
+
 	* testsuite/19_diagnostics/error_code/operators/bool_neg.cc: Move
 	dg-error to relevant line.
 	* testsuite/19_diagnostics/error_condition/operators/bool_neg.cc:

libstdc++-v3/testsuite/lib/libstdc++.exp

@@ -1925,6 +1925,8 @@ proc check_v3_target_little_endian { } {
     return $et_little_endian
 }
 
+# Return 1 if the Filesystem TS is suported, 0 otherwise.
+# Cache the result.
 proc check_v3_target_filesystem_ts { } {
     global cxxflags
     global DEFAULT_CXXFLAGS
@@ -1952,7 +1954,7 @@ proc check_v3_target_filesystem_ts { } {
 	set et_filesystem_ts 0
 
 	# Set up and preprocess a C++ test program that depends
-	# on debug mode activated.
+	# on the Filesystem TS feature-test macro being defined.
 	set src filesystem_ts[pid].cc
 
 	set f [open $src "w"]