tint: Add ast::ParameterList, use it

This is currently identical to ast::VariableList, but once we break
ast::Variable up, this will become a different vector type.

Bug: tint:1580
Change-Id: Ib2db5772996a63cd1989e36f1034dc1fbd3b371a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/93601
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Commit-Queue: Ben Clayton <bclayton@chromium.org>

src/tint/transform/calculate_array_length.cc

@@ -98,7 +98,7 @@ void CalculateArrayLength::Run(CloneContext& ctx, const DataMap&, DataMap&) cons
                 ctx.dst->Disable(ast::DisabledValidation::kIgnoreConstructibleFunctionParameter);
             ctx.dst->AST().AddFunction(ctx.dst->create<ast::Function>(
                 name,
-                ast::VariableList{
+                ast::ParameterList{
                     // Note: The buffer parameter requires the kStorage StorageClass
                     // in order for HLSL to emit this as a ByteAddressBuffer.
                     ctx.dst->create<ast::Variable>(ctx.dst->Sym("buffer"),

src/tint/transform/canonicalize_entry_point_io.cc

@@ -100,7 +100,7 @@ struct CanonicalizeEntryPointIO::State {
     const sem::Function* func_sem;
 
     /// The new entry point wrapper function's parameters.
-    ast::VariableList wrapper_ep_parameters;
+    ast::ParameterList wrapper_ep_parameters;
     /// The members of the wrapper function's struct parameter.
     ast::StructMemberList wrapper_struct_param_members;
     /// The name of the wrapper function's struct parameter.

src/tint/transform/combine_samplers.cc

@@ -169,7 +169,7 @@ struct CombineSamplers::State {
                 if (pairs.empty()) {
                     return nullptr;
                 }
-                ast::VariableList params;
+                ast::ParameterList params;
                 for (auto pair : func->TextureSamplerPairs()) {
                     const sem::Variable* texture_var = pair.first;
                     const sem::Variable* sampler_var = pair.second;

src/tint/transform/decompose_memory_access.cc

@@ -437,7 +437,7 @@ struct DecomposeMemoryAccess::State {
             auto* disable_validation =
                 b.Disable(ast::DisabledValidation::kIgnoreConstructibleFunctionParameter);
 
-            ast::VariableList params = {
+            ast::ParameterList params = {
                 // Note: The buffer parameter requires the StorageClass in
                 // order for HLSL to emit this as a ByteAddressBuffer or cbuffer
                 // array.
@@ -528,7 +528,7 @@ struct DecomposeMemoryAccess::State {
             auto* el_ast_ty = CreateASTTypeFor(ctx, el_ty);
             auto* disable_validation =
                 b.Disable(ast::DisabledValidation::kIgnoreConstructibleFunctionParameter);
-            ast::VariableList params{
+            ast::ParameterList params{
                 // Note: The buffer parameter requires the StorageClass in
                 // order for HLSL to emit this as a ByteAddressBuffer.
 
@@ -621,7 +621,7 @@ struct DecomposeMemoryAccess::State {
             // The first parameter to all WGSL atomics is the expression to the
             // atomic. This is replaced with two parameters: the buffer and offset.
 
-            ast::VariableList params = {
+            ast::ParameterList params = {
                 // Note: The buffer parameter requires the kStorage StorageClass in
                 // order for HLSL to emit this as a ByteAddressBuffer.
                 b.create<ast::Variable>(b.Sym("buffer"), ast::StorageClass::kStorage,

src/tint/transform/remove_phonies.cc

@@ -132,7 +132,7 @@ void RemovePhonies::Run(CloneContext& ctx, const DataMap&, DataMap&) const {
                     }
                     auto sink = utils::GetOrCreate(sinks, sig, [&] {
                         auto name = ctx.dst->Symbols().New("phony_sink");
-                        ast::VariableList params;
+                        ast::ParameterList params;
                         for (auto* ty : sig.types) {
                             auto* ast_ty = CreateASTTypeFor(ctx, ty);
                             params.push_back(

src/tint/transform/vertex_pulling.cc

@@ -228,7 +228,7 @@ struct State {
     Symbol pulling_position_name;
     Symbol struct_buffer_name;
     std::unordered_map<uint32_t, Symbol> vertex_buffer_names;
-    ast::VariableList new_function_parameters;
+    ast::ParameterList new_function_parameters;
 
     /// Generate the vertex buffer binding name
     /// @param index index to append to buffer name