tectonic: fix warnings related to old style definitions

-Wold-style-definition -Wstrict-prototypes

Author: ronnychevalier

tectonic/TECkit_Engine.h

@@ -208,7 +208,7 @@ TECkit_GetMappingFlags(
 */
 UInt32
 WINAPI EXPORTED
-TECkit_GetVersion();
+TECkit_GetVersion(void);
 
 /*
 	***** New APIs for version 2.1 of the engine *****

tectonic/XeTeXLayoutInterface.h

@@ -44,7 +44,7 @@ extern char gPrefEngine;
 int getCachedGlyphBBox(uint16_t fontID, uint16_t glyphID, GlyphBBox* bbox);
 void cacheGlyphBBox(uint16_t fontID, uint16_t glyphID, const GlyphBBox* bbox);
 
-void terminate_font_manager();
+void terminate_font_manager(void);
 
 XeTeXFont createFont(PlatformFontRef fontRef, Fixed pointSize);
 XeTeXFont createFontFromFile(const char* filename, int index, Fixed pointSize);
@@ -53,7 +53,7 @@ void setFontLayoutDir(XeTeXFont font, int vertical);
 
 PlatformFontRef findFontByName(const char* name, char* var, double size);
 
-char getReqEngine();
+char getReqEngine(void);
 void setReqEngine(char reqEngine);
 const char* getFullName(PlatformFontRef fontRef);
 

tectonic/dpx-pdfdev.c

@@ -1992,7 +1992,7 @@ pdf_dev_begin_actualtext (uint16_t *unicodes, int count)
 }
 
 void
-pdf_dev_end_actualtext ()
+pdf_dev_end_actualtext (void)
 {
   graphics_mode();
 

tectonic/dpx-pdfdev.h

@@ -222,6 +222,6 @@ extern void   pdf_dev_push_coord(double xpos, double ypos);
 extern void   pdf_dev_pop_coord(void);
 
 extern void   pdf_dev_begin_actualtext (uint16_t *unicodes, int len);
-extern void   pdf_dev_end_actualtext ();
+extern void   pdf_dev_end_actualtext (void);
 
 #endif /* _PDFDEV_H_ */