improve orca target

base/runtime/heap_allocator_orca.odin

@@ -0,0 +1,29 @@
+//+build orca
+//+private
+package runtime
+
+foreign {
+	@(link_name="malloc")   _orca_malloc   :: proc "c" (size: int) -> rawptr ---
+	@(link_name="calloc")   _orca_calloc   :: proc "c" (num, size: int) -> rawptr ---
+	@(link_name="free")     _orca_free     :: proc "c" (ptr: rawptr) ---
+	@(link_name="realloc")  _orca_realloc  :: proc "c" (ptr: rawptr, size: int) -> rawptr ---
+}
+
+_heap_alloc :: proc(size: int, zero_memory := true) -> rawptr {
+	if size <= 0 {
+		return nil
+	}
+	if zero_memory {
+		return _orca_calloc(1, size)
+	} else {
+		return _orca_malloc(size)
+	}
+}
+
+_heap_resize :: proc(ptr: rawptr, new_size: int) -> rawptr {
+	return _orca_realloc(ptr, new_size)
+}
+
+_heap_free :: proc(ptr: rawptr) {
+	_orca_free(ptr)
+}