Add break statement type determination.

This CL adds type determination for break statements.

Bug: tint:5
Change-Id: I5ca74a848ffd12fe404676910b08ea7518451eaf
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/18829
Reviewed-by: David Neto <dneto@google.com>

src/type_determiner.cc

@@ -15,6 +15,7 @@
 #include "src/type_determiner.h"
 
 #include "src/ast/assignment_statement.h"
+#include "src/ast/break_statement.h"
 #include "src/ast/scalar_constructor_expression.h"
 #include "src/ast/type_constructor_expression.h"
 
@@ -75,6 +76,10 @@ bool TypeDeterminer::DetermineResultType(ast::Statement* stmt) {
     auto a = stmt->AsAssign();
     return DetermineResultType(a->lhs()) && DetermineResultType(a->rhs());
   }
+  if (stmt->IsBreak()) {
+    auto b = stmt->AsBreak();
+    return DetermineResultType(b->conditional());
+  }
 
   error_ = "unknown statement type for type determination";
   return false;

src/type_determiner_test.cc

@@ -19,6 +19,7 @@
 
 #include "gtest/gtest.h"
 #include "src/ast/assignment_statement.h"
+#include "src/ast/break_statement.h"
 #include "src/ast/float_literal.h"
 #include "src/ast/int_literal.h"
 #include "src/ast/scalar_constructor_expression.h"
@@ -63,6 +64,20 @@ TEST_F(TypeDeterminerTest, Stmt_Assign) {
   EXPECT_TRUE(rhs_ptr->result_type()->IsF32());
 }
 
+TEST_F(TypeDeterminerTest, Stmt_Break) {
+  ast::type::I32Type i32;
+
+  auto cond = std::make_unique<ast::ScalarConstructorExpression>(
+      std::make_unique<ast::IntLiteral>(&i32, 2));
+  auto cond_ptr = cond.get();
+
+  ast::BreakStatement brk(ast::StatementCondition::kIf, std::move(cond));
+
+  EXPECT_TRUE(td()->DetermineResultType(&brk));
+  ASSERT_NE(cond_ptr->result_type(), nullptr);
+  EXPECT_TRUE(cond_ptr->result_type()->IsI32());
+}
+
 TEST_F(TypeDeterminerTest, Expr_Constructor_Scalar) {
   ast::type::F32Type f32;
   ast::ScalarConstructorExpression s(