gpu_angle_passthrough_fuzzer discovered a crash when glDrawArrays() is
called without a program bound. This was caused by assuming it's an
error to draw certain primitive types without a program bound, which is
incorrect. This fix is to mark all draw modes except Patches valid when
there is no program bound. Patches is handled separately by TS
validation.

Bug: chromium:1185267
Bug: angleproject:5483
Test: gpu_angle_passthrough_fuzzer
Test: SimpleOperationTest31.DrawWithoutProgramBound
Test: KHR-GLES31.core.draw_indirect.basic-mode-*adjacency
Change-Id: I294078b8695e0b8f36d3b7ad3c1aa71d2a275038
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2780971Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: Tim Van Patten <timvp@google.com>