Revert "Translator: Remove the SH_VALIDATE flag"

This reverts commit 4ca3d7d643.

Reason for revert: breaks roll into Chromium crrev.com/c/3213239
SH_VALIDATE is used in gpu_unittests.

Original change's description:
> Translator: Remove the SH_VALIDATE flag
>
> The SH_VALIDATE flag is a noop, defined as zero (0).
>
> Also move option descriptions up in the file.
>
> Bug: angleproject:6501
> Change-Id: I898106eb68b4508d8f94534cbff66652a69f4f3e
> Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3207360
> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
> Commit-Queue: Cody Northrop <cnorthrop@google.com>

Bug: angleproject:6501
Change-Id: Ia9983eac58a07e2a6e3d5fe4d1bfccfb9c48ccd0
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3212709
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>

include/GLSLANG/ShaderLang.h

@@ -82,19 +82,8 @@ enum ShShaderOutput
 // Compile options.
 // The Compile options type is defined in ShaderVars.h, to allow ANGLE to import the ShaderVars
 // header without needing the ShaderLang header. This avoids some conflicts with glslang.
-// SH_VALIDATE_LOOP_INDEXING: Validates loop and indexing in the shader to
-//                            ensure that they do not exceed the minimum
-//                            functionality mandated in GLSL 1.0 spec,
-//                            Appendix A, Section 4 and 5.
-//                            There is no need to specify this parameter when
-//                            compiling for WebGL - it is implied.
-// SH_OBJECT_CODE: Translates intermediate tree to glsl or hlsl shader, or SPIR-V binary.
-//                 Can be queried by calling sh::GetObjectCode().
-// SH_VARIABLES: Extracts attributes, uniforms, and varyings.
-//               Can be queried by calling ShGetVariableInfo().
-// SH_LINE_DIRECTIVES: Emits #line directives in HLSL.
-// SH_SOURCE_PATH: Tracks the source path for shaders.
-//                 Can be queried with getSourcePath().
+
+const ShCompileOptions SH_VALIDATE               = 0;
 const ShCompileOptions SH_VALIDATE_LOOP_INDEXING = UINT64_C(1) << 0;
 const ShCompileOptions SH_INTERMEDIATE_TREE      = UINT64_C(1) << 1;
 const ShCompileOptions SH_OBJECT_CODE            = UINT64_C(1) << 2;
@@ -656,7 +645,22 @@ void Destruct(ShHandle handle);
 // shaderStrings: Specifies an array of pointers to null-terminated strings containing the shader
 // source code.
 // numStrings: Specifies the number of elements in shaderStrings array.
-// compileOptions: A mask of compile options defined above.
+// compileOptions: A mask containing the following parameters:
+// SH_VALIDATE: Validates shader to ensure that it conforms to the spec
+//              specified during compiler construction.
+// SH_VALIDATE_LOOP_INDEXING: Validates loop and indexing in the shader to
+//                            ensure that they do not exceed the minimum
+//                            functionality mandated in GLSL 1.0 spec,
+//                            Appendix A, Section 4 and 5.
+//                            There is no need to specify this parameter when
+//                            compiling for WebGL - it is implied.
+// SH_INTERMEDIATE_TREE: Writes intermediate tree to info log.
+//                       Can be queried by calling sh::GetInfoLog().
+// SH_OBJECT_CODE: Translates intermediate tree to glsl or hlsl shader, or SPIR-V binary.
+//                 Can be queried by calling sh::GetObjectCode().
+// SH_VARIABLES: Extracts attributes, uniforms, and varyings.
+//               Can be queried by calling ShGetVariableInfo().
+//
 bool Compile(const ShHandle handle,
              const char *const shaderStrings[],
              size_t numStrings,

src/compiler/fuzz/translator_fuzzer.cpp

@@ -24,7 +24,7 @@ namespace
 
 // Options supported by any output
 constexpr ShCompileOptions kCommonOptions =
-    SH_VALIDATE_LOOP_INDEXING | SH_INTERMEDIATE_TREE | SH_OBJECT_CODE | SH_VARIABLES |
+    SH_VALIDATE | SH_VALIDATE_LOOP_INDEXING | SH_INTERMEDIATE_TREE | SH_OBJECT_CODE | SH_VARIABLES |
     SH_LINE_DIRECTIVES | SH_SOURCE_PATH | SH_REMOVE_INVARIANT_AND_CENTROID_FOR_ESSL3 |
     SH_EMULATE_ABS_INT_FUNCTION | SH_ENFORCE_PACKING_RESTRICTIONS | SH_CLAMP_INDIRECT_ARRAY_BOUNDS |
     SH_LIMIT_EXPRESSION_COMPLEXITY | SH_LIMIT_CALL_STACK_DEPTH | SH_INIT_GL_POSITION |