Fix gif encoding on x64 compiled with VS2017

bool is 1 byte on C++, not 4 bytes (int), so we cannot just "typedef int
bool" and assume that structs with bools will have the same size on C++
than on C.

third_party/giflib/lib/dgif_lib.c

@@ -236,7 +236,7 @@ int
 DGifGetScreenDesc(GifFileType *GifFile)
 {
     int BitsPerPixel;
-    bool SortFlag;
+    GifBool SortFlag;
     GifByteType Buf[3];
     GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
 

third_party/giflib/lib/egif_lib.c

@@ -57,7 +57,7 @@ static int EGifBufferedOutput(GifFileType * GifFile, GifByteType * Buf,
  info record. The Error member is cleared if successful.
 ******************************************************************************/
 GifFileType *
-EGifOpenFileName(const char *FileName, const bool TestExistence, int *Error)
+EGifOpenFileName(const char *FileName, const GifBool TestExistence, int *Error)
 {
 
     int FileHandle;
@@ -237,7 +237,7 @@ EGifGetGifVersion(GifFileType *GifFile)
  is 1 (numerically the same as bool true).  That way we'll even preserve
  object-file compatibility!
 ******************************************************************************/
-void EGifSetGifVersion(GifFileType *GifFile, const bool gif89)
+void EGifSetGifVersion(GifFileType *GifFile, const GifBool gif89)
 {
     GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
 
@@ -360,7 +360,7 @@ EGifPutImageDesc(GifFileType *GifFile,
                  const int Top,
                  const int Width,
                  const int Height,
-                 const bool Interlace,
+                 const GifBool Interlace,
                  const ColorMapObject *ColorMap)
 {
     GifByteType Buf[3];

third_party/giflib/lib/gif_lib.h

@@ -22,11 +22,12 @@ extern "C" {
 #ifdef HAVE_STDBOOL_H
   #include <stdbool.h>
 #elif !defined __cplusplus
-  typedef int bool;
   #define false 0
   #define true 1
 #endif
 
+typedef int GifBool;
+
 #define GIF_STAMP "GIFVER"          /* First chars in file - GIF stamp.  */
 #define GIF_STAMP_LEN sizeof(GIF_STAMP) - 1
 #define GIF_VERSION_POS 3           /* Version first character in stamp. */
@@ -46,13 +47,13 @@ typedef struct GifColorType {
 typedef struct ColorMapObject {
     int ColorCount;
     int BitsPerPixel;
-    bool SortFlag;
+    GifBool SortFlag;
     GifColorType *Colors;    /* on malloc(3) heap */
 } ColorMapObject;
 
 typedef struct GifImageDesc {
     GifWord Left, Top, Width, Height;   /* Current image dimensions. */
-    bool Interlace;                     /* Sequential/Interlaced lines. */
+    GifBool Interlace;                     /* Sequential/Interlaced lines. */
     ColorMapObject *ColorMap;           /* The local color map */
 } GifImageDesc;
 
@@ -118,7 +119,7 @@ typedef struct GraphicsControlBlock {
 #define DISPOSE_DO_NOT            1       /* Leave image in place */
 #define DISPOSE_BACKGROUND        2       /* Set area too background color */
 #define DISPOSE_PREVIOUS          3       /* Restore to previous content */
-    bool UserInputFlag;      /* User confirmation required before disposal */
+    GifBool UserInputFlag;      /* User confirmation required before disposal */
     int DelayTime;           /* pre-display delay in 0.01sec units */
     int TransparentColor;    /* Palette index for transparency, -1 if none */
 #define NO_TRANSPARENT_COLOR	-1
@@ -130,7 +131,7 @@ typedef struct GraphicsControlBlock {
 
 /* Main entry points */
 GifFileType *EGifOpenFileName(const char *GifFileName,
-                              const bool GifTestExistence, int *Error);
+                              const GifBool GifTestExistence, int *Error);
 GifFileType *EGifOpenFileHandle(const int GifFileHandle, int *Error);
 GifFileType *EGifOpen(void *userPtr, OutputFunc writeFunc, int *Error);
 int EGifSpew(GifFileType * GifFile);
@@ -158,9 +159,9 @@ int EGifPutScreenDesc(GifFileType *GifFile,
 int EGifPutImageDesc(GifFileType *GifFile, 
 		     const int GifLeft, const int GifTop,
                      const int GifWidth, const int GifHeight, 
-		     const bool GifInterlace,
+		     const GifBool GifInterlace,
                      const ColorMapObject *GifColorMap);
-void EGifSetGifVersion(GifFileType *GifFile, const bool gif89);
+void EGifSetGifVersion(GifFileType *GifFile, const GifBool gif89);
 int EGifPutLine(GifFileType *GifFile, GifPixelType *GifLine,
                 int GifLineLen);
 int EGifPutPixel(GifFileType *GifFile, const GifPixelType GifPixel);

third_party/giflib/lib/gif_lib_private.h

@@ -51,7 +51,7 @@ typedef struct GifFilePrivateType {
     GifByteType Suffix[LZ_MAX_CODE + 1];    /* So we can trace the codes. */
     GifPrefixType Prefix[LZ_MAX_CODE + 1];
     GifHashTableType *HashTable;
-    bool gif89;
+    GifBool gif89;
 } GifFilePrivateType;
 
 #endif /* _GIF_LIB_PRIVATE_H */