[PASS]Treat Halide call_type as pure expression (#2404)

HalideIR @ 6e7c1f04

-Subproject commit a08e26e5a97f4ef4d566a42f6c78704b3f9c7b8a
+Subproject commit 6e7c1f046fda536562dc80977e93324fee2324bd

tests/cpp/simple_passes_test.cc

+#include <dmlc/logging.h>
+#include <gtest/gtest.h>
+#include <tvm/tvm.h>
+#include <tvm/ir_pass.h>
+
+TEST(SimplePasses, HasSideEffect) {
+  using namespace tvm;
+  auto n = var("n");
+  Array<Expr> shape;
+  shape.push_back(n);
+
+  auto A = placeholder(shape, Float(32), "A");
+
+  CHECK(!tvm::ir::HasSideEffect(A[0]));
+}
+
+
+int main(int argc, char ** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  testing::FLAGS_gtest_death_test_style = "threadsafe";
+  return RUN_ALL_TESTS();
+}