Use a trampoline for all GL entry functions.

Bug swiftshader:64

Change-Id: Ice0e96934bae8628a14d628fd02046fc81f7a0ab
Reviewed-on: https://swiftshader-review.googlesource.com/c/19608
Reviewed-by: Alexis Hétu <sugoi@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>

src/OpenGL/libGLESv2/libGLESv2.vcxproj

diff --git a/src/OpenGL/libGLESv2/libGLESv2.vcxproj b/src/OpenGL/libGLESv2/libGLESv2.vcxproj
index 7bb3c72..5c0e73e 100644
--- a/src/OpenGL/libGLESv2/libGLESv2.vcxproj
+++ b/src/OpenGL/libGLESv2/libGLESv2.vcxproj
@@ -386,6 +386,7 @@
     <ClInclude Include="Buffer.h" />

     <ClInclude Include="Context.h" />

     <ClInclude Include="Device.hpp" />

+    <ClInclude Include="entry_points.h" />

     <ClInclude Include="Fence.h" />

     <ClInclude Include="Framebuffer.h" />

     <ClInclude Include="IndexDataManager.h" />