Stop resetting SanitizeAddress in TargetMachine::resetTargetOptions. NFC.

Instead of doing that, create a temporary copy of MCTargetOptions and reset its
SanitizeAddress field based on the function's attribute every time an InlineAsm
instruction is emitted in AsmPrinter::EmitInlineAsm. 

This is part of the work to remove TargetMachine::resetTargetOptions (the FIXME
added to TargetMachine.cpp in r236009 explains why this function has to be
removed).

Differential Revision: http://reviews.llvm.org/D9570

llvm-svn: 237412