Ignore unused function warnings from external headers when compiling with GCC and Clang (#3235)

src/rtext.c

@@ -71,12 +71,21 @@
 #include <ctype.h>          // Required for: toupper(), tolower() [Used in TextToUpper(), TextToLower()]
 
 #if defined(SUPPORT_FILEFORMAT_TTF)
+    #if defined(__GNUC__) // GCC and Clang
+        #pragma GCC diagnostic push
+        #pragma GCC diagnostic ignored "-Wunused-function"
+    #endif
+
     #define STB_RECT_PACK_IMPLEMENTATION
     #include "external/stb_rect_pack.h"     // Required for: ttf font rectangles packaging
 
     #define STBTT_STATIC
     #define STB_TRUETYPE_IMPLEMENTATION
     #include "external/stb_truetype.h"      // Required for: ttf font data reading
+
+    #if defined(__GNUC__) // GCC and Clang
+        #pragma GCC diagnostic pop
+    #endif
 #endif
 
 //----------------------------------------------------------------------------------

src/rtextures.c

@@ -138,6 +138,11 @@
      defined(SUPPORT_FILEFORMAT_PIC) || \
      defined(SUPPORT_FILEFORMAT_PNM))
 
+    #if defined(__GNUC__) // GCC and Clang
+        #pragma GCC diagnostic push
+        #pragma GCC diagnostic ignored "-Wunused-function"
+    #endif
+
     #define STBI_MALLOC RL_MALLOC
     #define STBI_FREE RL_FREE
     #define STBI_REALLOC RL_REALLOC
@@ -145,6 +150,10 @@
     #define STB_IMAGE_IMPLEMENTATION
     #include "external/stb_image.h"         // Required for: stbi_load_from_file()
                                             // NOTE: Used to read image data (multiple formats support)
+
+    #if defined(__GNUC__) // GCC and Clang
+        #pragma GCC diagnostic pop
+    #endif
 #endif
 
 #if (defined(SUPPORT_FILEFORMAT_DDS) || \
@@ -153,9 +162,18 @@
      defined(SUPPORT_FILEFORMAT_PVR) || \
      defined(SUPPORT_FILEFORMAT_ASTC))
 
+    #if defined(__GNUC__) // GCC and Clang
+        #pragma GCC diagnostic push
+        #pragma GCC diagnostic ignored "-Wunused-function"
+    #endif
+
     #define RL_GPUTEX_IMPLEMENTATION
     #include "external/rl_gputex.h"         // Required for: rl_load_xxx_from_memory()
                                             // NOTE: Used to read compressed textures data (multiple formats support)
+
+    #if defined(__GNUC__) // GCC and Clang
+        #pragma GCC diagnostic pop
+    #endif
 #endif
 
 #if defined(SUPPORT_FILEFORMAT_QOI)