libraw 0.16.1 started shipping some code that uses C++ exceptions. KDE code,
on the other hand, disables exceptions by default, and users must opt-in in
CMake to use them. clang is the exception and exceptions are always enabled
when using it, which is why the build did not break with it.
Import an upstream commit that does exactly that.
Bump PORTREVISION to make sure that all users build the port with exception
support.
Done in collaboration with alonso@.
PR: 200734
