Merge branch 'master' of https://github.com/recp/stb into working

stb_image.h

@@ -589,12 +589,18 @@ STBIDEF int   stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const ch
 #ifndef STBI_NO_THREAD_LOCALS
    #if defined(__cplusplus) &&  __cplusplus >= 201103L
       #define STBI_THREAD_LOCAL       thread_local
-   #elif defined (__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
-      #define STBI_THREAD_LOCAL       _Thread_local
-   #elif defined(__GNUC__)
+   #elif defined(__GNUC__) && __GNUC__ < 5
       #define STBI_THREAD_LOCAL       __thread
    #elif defined(_MSC_VER)
       #define STBI_THREAD_LOCAL       __declspec(thread)
+   #elif defined (__STDC_VERSION__) && __STDC_VERSION__ >= 201112L && !defined(__STDC_NO_THREADS__)
+      #define STBI_THREAD_LOCAL       _Thread_local
+   #endif
+
+   #ifndef STBI_THREAD_LOCAL
+      #if defined(__GNUC__)
+        #define STBI_THREAD_LOCAL       __thread
+      #endif
    #endif
 #endif