[llvm-branch-commits] [NFCI][ELF] Merge AgainstSymbol and AgainstSymbolWithTargetVA (PR #150798)

[Jessica Clarke via llvm-branch-commits]

https://github.com/jrtc27 created https://github.com/llvm/llvm-project/pull/150798

The former is just a special case of the latter, ignoring the expr and
always just using the addend. If we use R_ADDEND as expr (which
previously had no effect, and so was misleadingly R_ABS not R_ADDEND in
all but one use) then we don't need to maintain this as a separate case.

This just leaves MipsMultiGotPage as a special case; the only difference
between the other two Kind values is what needsDynSymIndex returns.