[builtins] Check __SEH__, when checking if ARM EHABI is implied
ARM EHABI isn't signalled by any specific compiler builtin define,
but is implied by the lack of defines specifying any other
exception handling mechanism, `__USING_SJLJ_EXCEPTIONS__` or
`__ARM_DWARF_EH__`.
As Windows SEH also can be used for unwinding, check for the
`__SEH__` define too, in the same way.
This is the same change as
4a3722a2c3dff1fe885cc38bf43d3c095c9851e7 /
D126866, applied on the compiler-rt builtins gcc_personality_v0
function.
Differential Revision: https://reviews.llvm.org/D126863