[Hexagon] llvm-options attribute is an array of strings (apache#9011)

Change the type from String to Array<String> in the code that looks
the attribute up.

src/target/llvm/codegen_hexagon.cc

@@ -671,11 +671,9 @@ runtime::Module BuildHexagon(IRModule mod, Target target) {
     }
     return vec;
   };
-  std::string llvm_options_str;
-  if (const Optional<String> llvm_options = target->GetAttr<String>("llvm-options")) {
-    llvm_options_str = "llvm," + llvm_options.value();
-  } else {
-    llvm_options_str = "llvm";
+  std::string llvm_options_str = "llvm";
+  if (const auto& llvm_options = target->GetAttr<Array<String>>("llvm-options")) {
+    for (const String& s : llvm_options.value()) llvm_options_str += "," + s;
   }
   // Postprocess the LLVM options string: replace '@' with '=', and ',' with ' '.
   for (int i = 0, e = llvm_options_str.size(); i != e; ++i) {

tests/python/unittest/test_target_codegen_hexagon.py

@@ -109,6 +109,18 @@ def test_alloc_vtcm():
     assert "HexagonBackendFreeVTCM" in calls
 
 
+def test_llvm_options():
+    if not check_prereq_and_setup():
+        return
+    target = tvm.target.hexagon("v66", llvm_options="-hexagon-noopt")
+    Zero = tvm.te.compute((10,), lambda _: tvm.tir.const(0, "int32"))
+    s = tvm.te.create_schedule(Zero.op)
+    tvm.build(s, [Zero], target=target, name="zero")
+    # Check that BuildHexagon hasn't crashed because of target attribute
+    # type mismatch.
+    assert re.search("-hexagon-noopt", str(target))
+
+
 def test_linked_params_codegen():
     if not check_prereq_and_setup():
         return
@@ -176,4 +188,5 @@ def test_linked_params_codegen():
     test_basic()
     test_llvm_target_features()
     test_alloc_vtcm()
+    test_llvm_options()
     test_linked_params_codegen()