patch 8.2.0621: after running tests asan files may remain

Problem:    After running tests asan files may remain.
Solution:   Clean up asan files with "make testclean".

src/Makefile

@@ -696,7 +696,8 @@ LINT_OPTIONS = -beprxzF
 # More at: https://code.google.com/p/address-sanitizer/
 # Useful environment variables:
 # $ export ASAN_OPTIONS="print_stacktrace=1 log_path=asan"
-# $ export LSAN_OPTIONS="suppressions=$cwd/testdir/lsan-suppress.txt"
+# $ export LSAN_OPTIONS="suppressions=`pwd`/testdir/lsan-suppress.txt"
+# When running tests output can be found in testdir/asan.*
 #SANITIZER_CFLAGS = -g -O0 -fsanitize=address -fno-omit-frame-pointer
 #SANITIZER_CFLAGS = -g -O0 -fsanitize=undefined -fno-omit-frame-pointer
 SANITIZER_LIBS = $(SANITIZER_CFLAGS)

src/testdir/Makefile

@@ -100,6 +100,7 @@ clean:
 	-rm -f opt_test.vim test.log test_result.log messages
 	-rm -f $(RM_ON_RUN) $(RM_ON_START)
 	-rm -f valgrind.*
+	-rm -f asan.*
 
 test1.out: test1.in
 	-rm -rf $*.failed $(RM_ON_RUN) $(RM_ON_START) wrongtermsize

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    621,
 /**/
     620,
 /**/