Add EH support to the MCJIT.

This gets exception handling working on ELF and Macho (x86-64 at least).
Other than the EH frame registration, this patch also implements support
for GOT relocations which are used to locate the personality function on
MachO.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181167 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/ExecutionEngine/SectionMemoryManager.h

@@ -72,6 +72,8 @@ public:
   /// \returns true if an error occurred, false otherwise.
   virtual bool applyPermissions(std::string *ErrMsg = 0);
 
+  void registerEHFrames(StringRef SectionData);
+
   /// This method returns the address of the specified function. As such it is
   /// only useful for resolving library symbols, not code generated symbols.
   ///