Revert "Fix the libbcc SHA1 checksum dependency"

This reverts commit 89175b9e4c07df1302374421096d6e1355954ace.
diff --git a/lib/ExecutionEngine/CacheWriter.cpp b/lib/ExecutionEngine/CacheWriter.cpp
index 86775a7..ab8dd03 100644
--- a/lib/ExecutionEngine/CacheWriter.cpp
+++ b/lib/ExecutionEngine/CacheWriter.cpp
@@ -93,6 +93,7 @@
   // Magic word and version
   memcpy(header->magic, OBCC_MAGIC, 4);
   memcpy(header->version, OBCC_VERSION, 4);
+  memcpy(header->libbcc_build_checksum, libbcc_build_checksum, 41);
 
   // Machine Integer Type
   uint32_t number = 0x00000001;