clover: Set appropriate flag defaults on memory object creation.
clover: Set appropriate flag defaults on memory object creation.

According to the spec when no device access mode is specified
clCreateBuffer and clCreateImage* should default to read/write, and
clCreateSubBuffer should default to the parent's device access flags.

clCreateSubBuffer is also required to inherit the host access and
host pointer flags from the parent.

Reviewed-and-tested-by: EdB <bbac3597f01acc7d927683e64659598a4321d5b2@sigluy.net>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler