Change resolveRelocation parameters so the relocations can find placeholder...

Change resolveRelocation parameters so the relocations can find placeholder values in the original object buffer.

Some ELF relocations require adding the a value to the original contents of the object buffer at the specified location.  In order to properly handle multiple applications of a relocation, the RuntimeDyld code should be grabbing the original value from the object buffer and writing a new value into the loaded section buffer.  This patch changes the parameters passed to resolveRelocations to accommodate this need.

llvm-svn: 167304