Renderbuffer objects are defined to have an initial internalformat of
GL_RGBA4, but the red/green/blue/alpha bits are 0. This inconsistency
is resolved by setting the internalformat to GL_NONE but reporting
GL_RGBA4 when queried.

Change-Id: Ie9a342c05eaa23f81773b37ebb942ca2e5b1addb
Reviewed-on: https://swiftshader-review.googlesource.com/14588Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>