Remove unsupported extension feature enums
Remove unsupported extension feature enums

Bug: b/176893525
Change-Id: I7fdaa013986d4c1702022a00d20479287cc69097
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/64729
Kokoro-Result: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Tested-by: Nicolas Capens <51edc787c30f24c4904e8ffbb5523c3a9f7a451d@google.com>
Reviewed-by: Alexis Hétu <1c7141772178a7e80858c3db5052b328076f08f4@google.com>
Commit-Queue: Nicolas Capens <51edc787c30f24c4904e8ffbb5523c3a9f7a451d@google.com>

google/swiftshader,google/swiftshader,google/swiftshader