Rename VariableStatement to VariableDeclStatement.

This CL renames VariableStatement to VariableDeclStatement to make it
clearer what it was modeling.

Bug: tint:25
Change-Id: Idd0d27fad7cc402f286e1abad74092c9d1961d91
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/18341
Reviewed-by: David Neto <dneto@google.com>
diff --git a/src/reader/wgsl/parser_impl.cc b/src/reader/wgsl/parser_impl.cc
index ad795bb..61aeeab 100644
--- a/src/reader/wgsl/parser_impl.cc
+++ b/src/reader/wgsl/parser_impl.cc
@@ -63,7 +63,7 @@
 #include "src/ast/unary_method_expression.h"
 #include "src/ast/unary_op.h"
 #include "src/ast/unary_op_expression.h"
-#include "src/ast/variable_statement.h"
+#include "src/ast/variable_decl_statement.h"
 #include "src/reader/wgsl/lexer.h"
 #include "src/type_manager.h"
 
@@ -1667,7 +1667,7 @@
 //   : variable_decl
 //   | variable_decl EQUAL logical_or_expression
 //   | CONST variable_ident_decl EQUAL logical_or_expression
-std::unique_ptr<ast::VariableStatement> ParserImpl::variable_stmt() {
+std::unique_ptr<ast::VariableDeclStatement> ParserImpl::variable_stmt() {
   auto t = peek();
   auto source = t.source();
   if (t.IsConst()) {
@@ -1702,7 +1702,7 @@
     var->set_is_const(true);
     var->set_constructor(std::move(constructor));
 
-    return std::make_unique<ast::VariableStatement>(source, std::move(var));
+    return std::make_unique<ast::VariableDeclStatement>(source, std::move(var));
   }
 
   auto var = variable_decl();
@@ -1724,7 +1724,7 @@
     var->set_constructor(std::move(constructor));
   }
 
-  return std::make_unique<ast::VariableStatement>(source, std::move(var));
+  return std::make_unique<ast::VariableDeclStatement>(source, std::move(var));
 }
 
 // if_stmt