[PATCH] [x86_64] Don't truncate PC-relative relocations in ELF EH frames to 32 bits

[Akos Kiss]

WebKit does JIT and yes, the sections get quite far away from each other, most of the time. The reason for this is that there are different allocators for the code and data sections.
http://trac.webkit.org/browser/trunk/Source/JavaScriptCore/ftl/FTLCompile.cpp?rev=173509#L53

I was "encouraged" to change the encoding to 64 bits by the mips64/mips64el solution.

http://reviews.llvm.org/D6079