Many new OpenGL ES 3 specific entries in Context::getIntegerv
were not hidden when an OpenGL ES 2 context is created. The
switch statement was separated in 2 statements in order to
fix this.

Change-Id: Ib218b72e854f5857958cfa14ecdfef5ae03ee92b
Reviewed-on: https://swiftshader-review.googlesource.com/8851Tested-by: Alexis Hétu <sugoi@google.com>
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>