scripts/check-obsolete-constructs.py: Process all headers as UTF-8.

A few of our installed headers contain UTF-8 in comments.
check-obsolete-constructs opened files without explicitly specifying
their encoding, so it would barf on these headers if “make check” was
run in a non-UTF-8 locale.

	* scripts/check-obsolete-constructs.py (HeaderChecker.check):
	Specify encoding="utf-8" when opening headers to check.

ChangeLog

@@ -1,3 +1,8 @@
+2019-03-14  Zack Weinberg  <zackw@panix.com>
+
+	* scripts/check-obsolete-constructs.py (HeaderChecker.check):
+	Specify encoding="utf-8" when opening headers to check.
+
 2019-03-13  Joseph Myers  <joseph@codesourcery.com>
 
 	* scripts/build-many-glibcs.py (Context.checkout): Default Linux

scripts/check-obsolete-constructs.py

@@ -437,7 +437,7 @@ class HeaderChecker:
     def check(self, fname):
         self.fname = fname
         try:
-            with open(fname, "rt") as fp:
+            with open(fname, "rt", encoding="utf-8") as fp:
                 contents = fp.read()
         except OSError as e:
             sys.stderr.write("{}: {}\n".format(fname, e.strerror))