backend/codegen, runtime: support interop intrinsics and natives

runtime/src/main/cpp/Natives.cpp

@@ -1,3 +1,6 @@
+#include <limits.h>
+#include <stdint.h>
+#include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
@@ -187,4 +190,22 @@ OBJ_GETTER0(Kotlin_konan_internal_undefined) {
   RETURN_OBJ(nullptr);
 }
 
+void* Kotlin_interop_malloc(KLong size, KInt align) {
+  if (size > SIZE_MAX) {
+    return nullptr;
+  }
+
+  void* result = malloc(size);
+  if ((reinterpret_cast<uintptr_t>(result) & (align - 1)) != 0) {
+    // Unaligned!
+    RuntimeAssert(false, "unsupported alignment");
+  }
+
+  return result;
+}
+
+void Kotlin_interop_free(void* ptr) {
+  free(ptr);
+}
+
 }  // extern "C"