Use a minimal non-blocking allocator for capstone

This is the only way it's possible to use it in a Stalker thread.
Make Script runtime's capstone allocations short-lived

Our capstone allocator is grow-only, so we want to keep the heap small.
Start migrating the last part of Gum from udis86 to capstone
Bring back gum_x86_reader_jcc_opcode_negate()
Port Stalker to capstone
Update Relocator tests to the new API
Fix incorrect handling of X86_OP_IMM
Fix Relocator regressions
Fix stack alignment in the `no_register_clobber` test
Fix Stalker regressions
Fix memory leak on relocator wrap-around
Fix shrinking logic in `gum_capstone_realloc`
Update to the capstone 3.0 API
Update to use the new modrm_offset field in our capstone branch
Fix Windows-specific warnings in the Socket script API
Fix Windows regressions
Merge branch 'feature/capstone'