gollvm: add top-level check target

Add 'check-gollvm' target for running libgo and gotools tests.
Ideally this would also run the unit tests; that can be added in
a subsequent patch.

Change-Id: I1dad643c0ea3ea0171abd6c0bc62dda4358ff723
Reviewed-on: https://go-review.googlesource.com/c/132599
Reviewed-by: Cherry Zhang <cherryyz@google.com>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 41ae721..a42d27f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -130,3 +130,5 @@
 # Subdir for unit tests
+# Top-level check target for gollvm
+add_custom_target(check-gollvm DEPENDS check-libgo check-gotools)