Fix glValidateProgram() not work as spec According spec ValidateProgram should detect error: Any two active samplers in the set of active program objects are of different types, but refer to the same texture image unit. Bug: angleproject:414259791 Change-Id: I2ab503b745cffdfb8be1a1ad649432fd8a73f63d Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6491669 Auto-Submit: Neil Zhang <Neil.Zhang@arm.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Alexey Knyazev <lexa.knyazev@gmail.com> Reviewed-by: Alexey Knyazev <lexa.knyazev@gmail.com>