tint/ast: Rename Builtin to BuiltinValue

This is what it is called in the spec, and avoids confusion with the builtin functions.

Change-Id: I5cd4a250351c10928e90b640a8c68c7834bcf2a0
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/97200
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
diff --git a/src/tint/writer/hlsl/generator_impl.cc b/src/tint/writer/hlsl/generator_impl.cc
index a9fddc3..8aa5d61 100644
--- a/src/tint/writer/hlsl/generator_impl.cc
+++ b/src/tint/writer/hlsl/generator_impl.cc
@@ -2981,29 +2981,29 @@
     return true;
 }
 
-std::string GeneratorImpl::builtin_to_attribute(ast::Builtin builtin) const {
+std::string GeneratorImpl::builtin_to_attribute(ast::BuiltinValue builtin) const {
     switch (builtin) {
-        case ast::Builtin::kPosition:
+        case ast::BuiltinValue::kPosition:
             return "SV_Position";
-        case ast::Builtin::kVertexIndex:
+        case ast::BuiltinValue::kVertexIndex:
             return "SV_VertexID";
-        case ast::Builtin::kInstanceIndex:
+        case ast::BuiltinValue::kInstanceIndex:
             return "SV_InstanceID";
-        case ast::Builtin::kFrontFacing:
+        case ast::BuiltinValue::kFrontFacing:
             return "SV_IsFrontFace";
-        case ast::Builtin::kFragDepth:
+        case ast::BuiltinValue::kFragDepth:
             return "SV_Depth";
-        case ast::Builtin::kLocalInvocationId:
+        case ast::BuiltinValue::kLocalInvocationId:
             return "SV_GroupThreadID";
-        case ast::Builtin::kLocalInvocationIndex:
+        case ast::BuiltinValue::kLocalInvocationIndex:
             return "SV_GroupIndex";
-        case ast::Builtin::kGlobalInvocationId:
+        case ast::BuiltinValue::kGlobalInvocationId:
             return "SV_DispatchThreadID";
-        case ast::Builtin::kWorkgroupId:
+        case ast::BuiltinValue::kWorkgroupId:
             return "SV_GroupID";
-        case ast::Builtin::kSampleIndex:
+        case ast::BuiltinValue::kSampleIndex:
             return "SV_SampleIndex";
-        case ast::Builtin::kSampleMask:
+        case ast::BuiltinValue::kSampleMask:
             return "SV_Coverage";
         default:
             break;