spirv: translate default-block uniforms

spirv: translate default-block uniforms

They are supported by SPIR-V for ARB_gl_spirv.

v2 (changes on top of Nicolai's original patch):
   * Handle UniformConstant storage class for uniforms other than
     samplers and images. (Eduardo Lima)
   * Handle location decoration also for samplers and images. (Eduardo
     Lima)
   * Rebase update (spirv_to_nir options added, logging changes, and
     others) (Alejandro Piñeiro)

Signed-off-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Signed-off-by: Eduardo Lima <elima@igalia.com>
Signed-off-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>