Gdiplus comments (#792)

* Attempt to remove clang 12 setup

* frida_gdiplus added to CI

* Redundancy note

* formatting again :\

* mistake of directory name

fuzzers/frida_gdiplus/src/fuzzer.rs

@@ -1,5 +1,11 @@
 //! A libfuzzer-like fuzzer with llmp-multithreading support and restarts
 //! The example harness is built for gdiplus.
+//! NOTE: This file is 1-to-1 copy of the ../../frida_libpng/fuzzer.rs, which
+//! is platform independent. Hence, this file contains code for other platforms
+//! but it's only meaningful for Windows because of the gdiplus target. If you
+//! going to make it compilable only for windows, don't foret to modify the
+//! scripts/test_all_fuzzers.sh to opt-out this fuzzer from that test.
+
 use mimalloc::MiMalloc;
 #[global_allocator]
 static GLOBAL: MiMalloc = MiMalloc;