patch 8.1.2342: random number generator in Vim script is slow

Problem:    Random number generator in Vim script is slow.
Solution:   Add rand() and srand(). (Yasuhiro Matsumoto, closes #1277)
diff --git a/src/testdir/Make_all.mak b/src/testdir/Make_all.mak
index ac25420..f6d6c17 100644
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -211,6 +211,7 @@
 	test_pyx3 \
 	test_quickfix \
 	test_quotestar \
+	test_random \
 	test_recover \
 	test_regex_char_classes \
 	test_regexp_latin \
@@ -403,6 +404,7 @@
 	test_pyx3.res \
 	test_quickfix.res \
 	test_quotestar.res \
+	test_random.res \
 	test_regex_char_classes.res \
 	test_registers.res \
 	test_restricted.res \