[ARM] Do not perform a tail call when the caller returns several values.
The fix is slightly different then x86 (see r216117) because the number of values
attached to a return can vary even for a single returned value (e.g., f64 yields
two returned values).

<rdar://problem/18352998>
[PECOFF] /safeseh:no on x64 is not an error

I made LLD to report an error if /safeseh:no option is given on x64,
but it turned out MSVC link.exe doesn't report error on it.
Removing the check.