[XRay] Make llvm.xray.typedevent parameter type match __xray_typedevent

The Clang built-in function is void __xray_typedevent(size_t, const void *, size_t),
but the LLVM intrinsics has smaller integer types. Since we only allow
64-bit ELF/Mach-O targets, we can change llvm.xray.typedevent to
i64/ptr/i64.

This allows encoding more information and avoids i16 legalization for
many non-X86 targets.

fdrLoggingHandleTypedEvent only supports uint16_t event type.