Enable streaming of bitcode

This CL delays reading of function bodies from initial parse until
materialization, allowing overlap of compilation with bitcode download.

llvm-svn: 149918
diff --git a/llvm/lib/Support/MemoryObject.cpp b/llvm/lib/Support/MemoryObject.cpp
index b20ab89..c82f46a 100644
--- a/llvm/lib/Support/MemoryObject.cpp
+++ b/llvm/lib/Support/MemoryObject.cpp
@@ -16,7 +16,7 @@
 int MemoryObject::readBytes(uint64_t address,
                             uint64_t size,
                             uint8_t* buf,
-                            uint64_t* copied) const {
+                            uint64_t* copied) {
   uint64_t current = address;
   uint64_t limit = getBase() + getExtent();