The spec for GetProgramiv didn't mention anything about
PROGRAM_BINARY_LENGTH, but looking at the OpenGL ES 3.0
spec, section 2.11.4 - "Program Binaries", we have:

"The number of bytes in the program binary can be queried
by calling GetProgramiv with pname PROGRAM_BINARY_LENGTH"

Change-Id: Idf652fec34fa1f3cce6cce0e7302ab8d47a6cf74
Reviewed-on: https://swiftshader-review.googlesource.com/3611Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>