Change well known method `String.charAt()` to `ArtMethod*`.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Change-Id: Idb34c5de408b98db746d385ae6e012a8997fcc96
diff --git a/runtime/native/string_array_utils.h b/runtime/native/string_array_utils.h
new file mode 100644
index 0000000..41d5093
--- /dev/null
+++ b/runtime/native/string_array_utils.h
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_RUNTIME_NATIVE_STRING_ARRAY_UTILS_H_
+#define ART_RUNTIME_NATIVE_STRING_ARRAY_UTILS_H_
+
+#include "base/locks.h"
+#include "class_root-inl.h"
+#include "handle_scope-inl.h"
+#include "mirror/object_array-alloc-inl.h"
+#include "mirror/string.h"
+
+namespace art {
+
+namespace detail {
+
+inline const char* GetStringCStr(const char* str) { return str; }
+inline const char* GetStringCStr(const std::string& str) { return str.c_str(); }
+
+}  // namespace detail
+
+template <typename Container>
+ObjPtr<mirror::ObjectArray<mirror::String>> CreateStringArray(
+    Thread* self, size_t size, const Container& entries) REQUIRES_SHARED(Locks::mutator_lock_) {
+  StackHandleScope<1u> hs(self);
+  Handle<mirror::ObjectArray<mirror::String>> array = hs.NewHandle(
+      mirror::ObjectArray<mirror::String>::Alloc(
+          self, GetClassRoot<mirror::ObjectArray<mirror::String>>(), size));
+  if (array == nullptr) {
+    DCHECK(self->IsExceptionPending());
+    return nullptr;
+  }
+  // Note: If the container's iterator returns a `std::string` by value, the `auto&&`
+  // binds as a const reference and extends the lifetime of the temporary object.
+  size_t pos = 0u;
+  for (auto&& entry : entries) {
+    ObjPtr<mirror::String> oentry =
+        mirror::String::AllocFromModifiedUtf8(self, detail::GetStringCStr(entry));
+    if (oentry == nullptr) {
+      DCHECK(self->IsExceptionPending());
+      return nullptr;
+    }
+    // We're initializing a newly allocated array object, so we do not need to record that under
+    // a transaction. If the transaction is aborted, the whole object shall be unreachable.
+    DCHECK_LT(pos, size);
+    array->SetWithoutChecks</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
+        pos, oentry);
+    ++pos;
+  }
+  DCHECK_EQ(pos, size);
+  return array.Get();
+}
+
+template <typename Container>
+ObjPtr<mirror::ObjectArray<mirror::String>> CreateStringArray(
+    Thread* self, const Container& entries) REQUIRES_SHARED(Locks::mutator_lock_) {
+  return CreateStringArray(self, entries.size(), entries);
+}
+
+inline ObjPtr<mirror::ObjectArray<mirror::String>> CreateStringArray(
+    Thread* self, std::initializer_list<const char*> entries)
+    REQUIRES_SHARED(Locks::mutator_lock_) {
+  return CreateStringArray<std::initializer_list<const char*>>(self, entries);
+}
+
+}  // namespace art
+
+#endif  // ART_RUNTIME_NATIVE_STRING_ARRAY_UTILS_H_