[tint] Remove current_function from ValidateFunction.

The ValidateFunction method just required the current pipeline stage.
Provide the stage directly instead of using current_function.

Bug: tint:1313
Change-Id: I0c12bef4b28b9cecfbd2b9d7d336a8ff3f8c3a77
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/87144
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>

src/tint/resolver/resolver.cc

@@ -699,7 +699,10 @@ sem::Function* Resolver::Function(const ast::Function* decl) {
     return nullptr;
   }
 
-  if (!ValidateFunction(func)) {
+  auto stage = current_function_
+                   ? current_function_->Declaration()->PipelineStage()
+                   : ast::PipelineStage::kNone;
+  if (!ValidateFunction(func, stage)) {
     return nullptr;
   }
 

src/tint/resolver/resolver.h

@@ -260,7 +260,7 @@ class Resolver {
   bool ValidateEntryPoint(const sem::Function* func, ast::PipelineStage stage);
   bool ValidateForLoopStatement(const sem::ForLoopStatement* stmt);
   bool ValidateFallthroughStatement(const sem::Statement* stmt);
-  bool ValidateFunction(const sem::Function* func);
+  bool ValidateFunction(const sem::Function* func, ast::PipelineStage stage);
   bool ValidateFunctionCall(const sem::Call* call);
   bool ValidateGlobalVariable(const sem::Variable* var);
   bool ValidateIfStatement(const sem::IfStatement* stmt);

src/tint/resolver/resolver_validation.cc

@@ -832,7 +832,8 @@ bool Resolver::ValidateInterpolateAttribute(
   return true;
 }
 
-bool Resolver::ValidateFunction(const sem::Function* func) {
+bool Resolver::ValidateFunction(const sem::Function* func,
+                                ast::PipelineStage stage) {
   auto* decl = func->Declaration();
 
   auto name = builder_->Symbols().NameFor(decl->symbol);
@@ -917,9 +918,6 @@ bool Resolver::ValidateFunction(const sem::Function* func) {
   }
 
   if (decl->IsEntryPoint()) {
-    auto stage = current_function_
-                     ? current_function_->Declaration()->PipelineStage()
-                     : ast::PipelineStage::kNone;
     if (!ValidateEntryPoint(func, stage)) {
       return false;
     }