Export ZSTD_LEGACY_SUPPORT in tests/Makefile (#3955)

This doesn't affect most of the targets, but will help me sleep better at night knowing that future refactors won't break the legacy support.

Should have been included in https://github.com/facebook/zstd/pull/3943 but I noticed after that merged, so putting up a separate PR.

diff --git a/tests/Makefile b/tests/Makefile
index 3550b7a9c621147773e49291ad043bdbdfaa02b8..ed3692a24e8df2d0b061fb40eee0bc584302adde 100644 (file)
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -21,6 +21,7 @@
 # ##########################################################################
 
 ZSTD_LEGACY_SUPPORT ?= 5
+export ZSTD_LEGACY_SUPPORT
 
 DEBUGLEVEL ?= 2
 export DEBUGLEVEL  # transmit value to sub-makefiles