Add type determination for the regardless statement.

This CL adds the type determination code for the Regardless statement.

Bug: tint:5
Change-Id: I8485800f3e19130101917d8175e8111aa196828c
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/18836
Reviewed-by: David Neto <dneto@google.com>

src/type_determiner.cc

@@ -21,6 +21,7 @@
 #include "src/ast/else_statement.h"
 #include "src/ast/if_statement.h"
 #include "src/ast/loop_statement.h"
+#include "src/ast/regardless_statement.h"
 #include "src/ast/scalar_constructor_expression.h"
 #include "src/ast/type_constructor_expression.h"
 
@@ -123,6 +124,11 @@ bool TypeDeterminer::DetermineResultType(ast::Statement* stmt) {
     return DetermineResultType(l->body()) &&
            DetermineResultType(l->continuing());
   }
+  if (stmt->IsRegardless()) {
+    auto r = stmt->AsRegardless();
+    return DetermineResultType(r->condition()) &&
+           DetermineResultType(r->body());
+  }
   if (stmt->IsNop()) {
     return true;
   }

src/type_determiner_test.cc

@@ -27,6 +27,7 @@
 #include "src/ast/if_statement.h"
 #include "src/ast/int_literal.h"
 #include "src/ast/loop_statement.h"
+#include "src/ast/regardless_statement.h"
 #include "src/ast/scalar_constructor_expression.h"
 #include "src/ast/type/f32_type.h"
 #include "src/ast/type/i32_type.h"
@@ -247,6 +248,36 @@ TEST_F(TypeDeterminerTest, Stmt_Loop) {
   EXPECT_TRUE(continuing_rhs_ptr->result_type()->IsF32());
 }
 
+TEST_F(TypeDeterminerTest, Stmt_Regardless) {
+  ast::type::I32Type i32;
+  ast::type::F32Type f32;
+
+  auto lhs = std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::IntLiteral>(&i32, 2));
+  auto lhs_ptr = lhs.get();
+
+  auto rhs = std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::FloatLiteral>(&f32, 2.3f));
+  auto rhs_ptr = rhs.get();
+
+  ast::StatementList body;
+  body.push_back(std::make_unique<ast::AssignmentStatement>(std::move(lhs),
+                                                            std::move(rhs)));
+
+  ast::RegardlessStatement regardless(
+      std::make_unique<ast::ScalarConstructorExpression>(
+          std::make_unique<ast::IntLiteral>(&i32, 3)),
+      std::move(body));
+
+  EXPECT_TRUE(td()->DetermineResultType(&regardless));
+  ASSERT_NE(regardless.condition()->result_type(), nullptr);
+  ASSERT_NE(lhs_ptr->result_type(), nullptr);
+  ASSERT_NE(rhs_ptr->result_type(), nullptr);
+  EXPECT_TRUE(regardless.condition()->result_type()->IsI32());
+  EXPECT_TRUE(lhs_ptr->result_type()->IsI32());
+  EXPECT_TRUE(rhs_ptr->result_type()->IsF32());
+}
+
 TEST_F(TypeDeterminerTest, Expr_Constructor_Scalar) {
   ast::type::F32Type f32;
   ast::ScalarConstructorExpression s(