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>
diff --git a/src/type_determiner.cc b/src/type_determiner.cc
index 87bf07a..8eed309 100644
--- a/src/type_determiner.cc
+++ b/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 @@
     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;