Add vstore_half helpers for ptx

Reviewed-by: Jan Vesely <jan.vesely@rutgers.edu>
llvm-svn: 314925
diff --git a/libclc/ptx/lib/SOURCES_4.0 b/libclc/ptx/lib/SOURCES_4.0
new file mode 100644
index 0000000..5851798
--- /dev/null
+++ b/libclc/ptx/lib/SOURCES_4.0
@@ -0,0 +1 @@
+shared/vstore_half_helpers.ll