[HIP] fix long double size

For amdgpu target long double type is the same as double type.
The width and align of long double type was incorrectly
overridden when copying aux target properties, which
caused assertion in codegen when emitting global
variables with long double type.

This patch fix that by saving and restoring width
and align of long double type.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D127771

Fixes: SWDEV-335515