[MC] Disable MCAssembler based constant folding for DwarfDebug

Related to the poor performance of MCAssembler based constant folding
(see `bool MCExpr::evaluateAsAbsolute(int64_t &Res, const MCAssembler *Asm) const` and
`AttemptToFoldSymbolOffsetDifference`),
commit 9500a5d0 (#91082) caused -O0 -g
compile time regression.

9500a5d0 special cased .eh_frame FDE
emitting. This patch adds a special case to .debug_* emitting as well to
mitigate the rest regression.

The MCAssembler based constant folding strategy should be improved to
remove the two special cases.