Fix Visual Studio 2015 compilation issues.

Change-Id: I1ec7075cbc53318a0e788672501519f302278298
Reviewed-on: https://swiftshader-review.googlesource.com/5780
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>

src/OpenGL/libEGL/Display.h

diff --git a/src/OpenGL/libEGL/Display.h b/src/OpenGL/libEGL/Display.h
index 456c1f2..acd639a 100644
--- a/src/OpenGL/libEGL/Display.h
+++ b/src/OpenGL/libEGL/Display.h
@@ -31,8 +31,8 @@
 	class Context;
 	class Image;
 
-	const EGLDisplay PRIMARY_DISPLAY = (EGLDisplay)1;
-	const EGLDisplay HEADLESS_DISPLAY = (EGLDisplay)0xFACE1E55;
+	const EGLDisplay PRIMARY_DISPLAY  = reinterpret_cast<EGLDisplay>((intptr_t)1);
+	const EGLDisplay HEADLESS_DISPLAY = reinterpret_cast<EGLDisplay>((intptr_t)0xFACE1E55);
 
 	class Display
 	{