Turning on warnings as error in Visual Studio

Disabled a few warnings and fixed a few warnings to enable
turning 'warnings as errors' on in Visual Studio.

Change-Id: I91e8e2d4d71794b73178f8d59c2f6fc872ad3085
Reviewed-on: https://swiftshader-review.googlesource.com/5710
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
diff --git a/src/OpenGL/libGLESv2/libGLESv3.cpp b/src/OpenGL/libGLESv2/libGLESv3.cpp
index 7f362bf..f4bef0f 100644
--- a/src/OpenGL/libGLESv2/libGLESv3.cpp
+++ b/src/OpenGL/libGLESv2/libGLESv3.cpp
@@ -3481,7 +3481,7 @@
 		return error(GL_INVALID_ENUM);
 	}
 
-	if(!ValidateTexParamParameters(pname, *param))
+	if(!ValidateTexParamParameters(pname, static_cast<GLint>(roundf(*param))))
 	{
 		return;
 	}