Log Message:
llvm: Change how sys/regset.h workaround is implemented.

Previously a special override header was used via an additional include path,
but this extra include path was not exported to llvm-config so while llvm was
ok, dependencies wouldn't find the header and fail.

Instead just pull the changes directly inline into DataTypes.h so that they
are available everywhere.  Fixes the clang build on SunOS.  Bump PKGREVISION.