[DWARF] - Cleanup relocations proccessing.

RelocAddrMap was a pair of <width, address>, where width is relocation size (4/8/x, x < 8), 
and width field was never used in code.

Relocations proccessing loop had checks for width field. Does not look like DWARF parser
should do that. There is probably no much sense to validate relocations during proccessing 
them in parser.

Patch removes relocation's width relative code from DWARFContext.

Differential revision: https://reviews.llvm.org/D33194

llvm-svn: 303251