[spirv-writer] Handle bitwise or expression.

This CL adds output of the bitwise or command.

Bug: tint:5
Change-Id: Iad9bafaa0a8394494615922c14c2d33d2d5701bb
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/19409
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
diff --git a/src/writer/spirv/builder.cc b/src/writer/spirv/builder.cc
index 408ea4b..1bdb0ad 100644
--- a/src/writer/spirv/builder.cc
+++ b/src/writer/spirv/builder.cc
@@ -615,6 +615,8 @@
     }
   } else if (expr->IsNotEqual()) {
     op = lhs_is_float_or_vec ? spv::Op::OpFOrdNotEqual : spv::Op::OpINotEqual;
+  } else if (expr->IsOr()) {
+    op = spv::Op::OpBitwiseOr;
   } else {
     return 0;
   }
diff --git a/src/writer/spirv/builder_binary_expression_test.cc b/src/writer/spirv/builder_binary_expression_test.cc
index 8da3eb8..2ee5a0e 100644
--- a/src/writer/spirv/builder_binary_expression_test.cc
+++ b/src/writer/spirv/builder_binary_expression_test.cc
@@ -122,7 +122,8 @@
     BuilderTest,
     BinaryArithIntegerTest,
     testing::Values(BinaryData{ast::BinaryOp::kAdd, "OpIAdd"},
-                    BinaryData{ast::BinaryOp::kAnd, "OpBitwiseAnd"}));
+                    BinaryData{ast::BinaryOp::kAnd, "OpBitwiseAnd"},
+                    BinaryData{ast::BinaryOp::kOr, "OpBitwiseOr"}));
 
 using BinaryArithFloatTest = testing::TestWithParam<BinaryData>;
 TEST_P(BinaryArithFloatTest, Scalar) {