[MC] Disable MCAssembler based constant folding for compact unwind and emitJumpTableEntry

Similar to commit 245491a9 for DwarfDebug.

This completely disables the expensive MCFragment walk code in
`AttemptToFoldSymbolOffsetDifference` when compiling sqlite3.i for
macOS.

In the future, we should try enabling the MCFragment walk only for
constructs like `.if . -_start == 1` and `.subsection a-b` and
remove these `setUseAssemblerInfoForParsing`.