os/os2: add get_executable_path and get_executable_directory

core/os/os2/path_darwin.odin

@@ -0,0 +1,31 @@
+package os2
+
+import "base:runtime"
+
+import "core:sys/darwin"
+import "core:sys/posix"
+
+_get_executable_path :: proc(allocator: runtime.Allocator) -> (path: string, err: Error) {
+	size: u32
+
+	ret := darwin._NSGetExecutablePath(nil, &size)
+	assert(ret == -1)
+	assert(size > 0)
+
+	TEMP_ALLOCATOR_GUARD()
+
+	buf := make([]byte, size, temp_allocator()) or_return
+	assert(u32(len(buf)) == size)
+
+	ret = darwin._NSGetExecutablePath(raw_data(buf), &size)
+	assert(ret == 0)
+
+	real := posix.realpath(cstring(raw_data(buf)))
+	if real == nil {
+		err = _get_platform_error()
+		return
+	}
+	defer posix.free(real)
+
+	return clone_string(string(real), allocator)
+}