[MachO] Tweak handling of LC_FUNCTION_STARTS

`LC_FUNCTION_STARTS` includes both functions and jump tables. We want to
avoid calling `AddFunctionForAnalysis` on jump tables since it can
result in a function being created at the jump table's location with a
bogus body.

We already skip adding functions for entries in `LC_FUNCTION_STARTS` if
the lifting of their first few bytes end up including `LLIL_UNDEF`.
However, arm64 intentionally lifts `udf` instructions (i.e., opcodes in
the Permanently Undefined range) to `LLIL_TRAP` in order to preserve the
immediate portion of the instruction.

To address this, `MachoView::IsValidFunctionStart` now returns false if
the first lifted instruction is `LLIL_TRAP` in addition to when the
lifting contains `LLIL_UNDEF`.

0 files changed, 0 insertions, 0 deletions