Fix error code on invalid shader/program operation

Fix error code on invalid shader/program operation

The spec states that GL_INVALID_OPERATION is generated when a shader or
program function is called on the wrong object type. GL_INVALID_VALUE is
generated when there's no shader nor program object by that name.

Change-Id: Id9d922b390ca5d2db233eb60b6a44992105cb933
Reviewed-on: https://swiftshader-review.googlesource.com/5176
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>