When the non-local symbol in the expression is in the same fragment
as the second symbol, the assembler can still evaluate the expression
without needing a relocation.
For example, on ARM:
_foo:
ldr lr, (_foo - 4)
rdar://10348687
llvm-svn: 148341
When the file isn't being built with subsections-via-symbols, symbol
differences involving non-local symbols can be resolved more aggressively.
Needed for gas compatibility.
llvm-svn: 146054