updated for version 7.4.497
Problem:    With some regexp patterns the NFA engine uses many states and
            becomes very slow.  To the user it looks like Vim freezes.
Solution:   When the number of states reaches a limit fall back to the old
            engine. (Christian Brabandt)
diff --git a/src/testdir/Make_os2.mak b/src/testdir/Make_os2.mak
index 5f3dc13..3b6b407 100644
--- a/src/testdir/Make_os2.mak
+++ b/src/testdir/Make_os2.mak
@@ -50,6 +50,8 @@
 		test_signs.out \
 		test_utf8.out
 
+SCRIPTS_BENCH = bench_re_freeze.out
+
 .SUFFIXES: .in .out
 
 all:	/tmp $(SCRIPTS)
@@ -57,6 +59,8 @@
 
 $(SCRIPTS): $(VIMPROG)
 
+benchmark: $(SCRIPTS_BENCH)
+
 clean:
 	-rm -rf *.out Xdotest test.ok tiny.vim small.vim mbyte.vim viminfo
 
@@ -75,3 +79,10 @@
 # Create a directory for temp files
 /tmp:
 	-mkdir /tmp
+
+bench_re_freeze.out: bench_re_freeze.vim
+	-del $*.failed test.ok benchmark.out
+	copy $*.ok test.ok
+	$(VIMPROG) -u os2.vim --noplugin -s dotest.in $*.in
+	type benchmark.out
+