[DebugInfo] Add DW_OP_LLVM_extract_bits (#93990)

This operation extracts a number of bits at a given offset and sign or
zero extends them, which is done by emitting it as a left shift followed
by a right shift.

This is being added for use in clang for C++ structured bindings of
bitfields that have offset or size that aren't a byte multiple. A new
operation is being added, instead of shifts being used directly, as it
makes correctly handling it in optimisations (which will be done in a
later patch) much easier.