cmd/compile: enable panic+recover adjustment for some ABI wrappers
For most ABI wrappers we don't need it because we're never going
to defer an ABI wrapper for a function that then recovers, so
that's would just be unnecessary code in the ABI wrapper.
However, for functions that could be on the path of invoking a
deferred function that can recover (runtime.reflectcall,
reflect.callReflect, and reflect.callMethod), we do want the
panic+recover adjustment. Set the Wrapper flag for them.
Currently, those functions are defined as ABIInternal to avoid
the ABI wrappers. But the assembly code still follows ABI0
calling convention, which would not work with the register-based
calling convention. In particlar, it is not possible to make
runtime.reflectcall ABIInternal, because it tail calls
runtime.callNN functions, which are splittable. Later CLs will
make them ABI0 and use the wrappers.