- Fixes https://github.com/llvm/llvm-project/issues/166512
- `ComplexExprEmitter::EmitCompoundAssignLValue` is calling
`EmitLoadOfScalar(LValue, SourceLocation)` to load the LHS value in the
case that it's non-complex, however this function requires that the
value is a simple LValue - issue occurred because the LValue in question
was a bitfield LValue. I changed it to use this function which seems to
handle all of the different cases (deferring to the original
`EmitLoadOfScalar` if it's a simple LValue)
60a27953ea
