Use S_ISDIR instead of S_IFMT/S_IFDIR to fix building with gcc in c11 mode.

src/espeak.c

@@ -114,7 +114,7 @@ int GetFileLength(const char *filename)
 	if(stat(filename,&statbuf) != 0)
 		return(0);
 
-	if((statbuf.st_mode & S_IFMT) == S_IFDIR)
+	if(S_ISDIR(statbuf.st_mode))
 		return(-2);  // a directory
 
 	return(statbuf.st_size);

src/libespeak-ng/speak_lib.c

@@ -298,8 +298,7 @@ int GetFileLength(const char *filename)
 	if(stat(filename,&statbuf) != 0)
 		return(0);
 
-	if((statbuf.st_mode & S_IFMT) == S_IFDIR)
-		//	if(S_ISDIR(statbuf.st_mode))
+	if(S_ISDIR(statbuf.st_mode))
 		return(-2);  // a directory
 
 	return(statbuf.st_size);

src/speak.c

@@ -138,8 +138,7 @@ int GetFileLength(const char *filename)
 	if(stat(filename,&statbuf) != 0)
 		return(0);
 
-	if((statbuf.st_mode & S_IFMT) == S_IFDIR)
-//	if(S_ISDIR(statbuf.st_mode))
+	if(S_ISDIR(statbuf.st_mode))
 		return(-2);  // a directory
 
 	return(statbuf.st_size);