Vulkan: No-op on ProgramVk::Validate implementation

Also enable the dEQP test that was blocked on that UNIMPLEMENTED call.

Bug: angleproject:2600
Change-Id: Iae1280d6e4f52c5b8e66c9f7fbaa9b2730c4eb0e
Reviewed-on: https://chromium-review.googlesource.com/1085693
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Luc Ferron <lucferron@chromium.org>
diff --git a/src/libANGLE/renderer/vulkan/ProgramVk.cpp b/src/libANGLE/renderer/vulkan/ProgramVk.cpp
index 121b8e5..6334ae4 100644
--- a/src/libANGLE/renderer/vulkan/ProgramVk.cpp
+++ b/src/libANGLE/renderer/vulkan/ProgramVk.cpp
@@ -397,8 +397,8 @@
 
 GLboolean ProgramVk::validate(const gl::Caps &caps, gl::InfoLog *infoLog)
 {
-    UNIMPLEMENTED();
-    return GLboolean();
+    // No-op. The spec is very vague about the behavior of validation.
+    return GL_TRUE;
 }
 
 template <typename T>