Re-factored RuntimeDyLd:

1. The main works will made in the RuntimeDyLdImpl with uses the ObjectFile class. RuntimeDyLdMachO and RuntimeDyLdELF now only parses relocations and resolve it. This is allows to make improvements of the RuntimeDyLd more easily. In addition the support for COFF can be easily added.

2. Added ARM relocations to RuntimeDyLdELF.

3. Added support for stub functions for the ARM, allowing to do a long branch.

4. Added support for external functions that are not loaded from the object files, but can be loaded from external libraries. Now MCJIT can correctly execute the code containing the printf, putc, and etc.

5. The sections emitted instead functions, thanks Jim Grosbach. MemoryManager.startFunctionBody() and MemoryManager.endFunctionBody() have been removed.
6. MCJITMemoryManager.allocateDataSection() and MCJITMemoryManager. allocateCodeSection() used JMM->allocateSpace() instead of JMM->allocateCodeSection() and JMM->allocateDataSection(), because I got an error: "Cannot allocate an allocated block!" with object file contains more than one code or data sections.

llvm-svn: 153754