Ensure that stdc headers are included in HDF5 builds.

Without this, static MSVC builds don't compile ('FILE' isn't defined).

ThirdParty/hdf5/CMakeLists.txt

@@ -62,6 +62,10 @@ if(HDF5_ENABLE_Z_LIB_SUPPORT)
   set(H5_ZLIB_HEADER "vtk_zlib.h")
 endif()
 
+# Ensure that the proper headers are included. Without this, static MSVC builds
+# do not compile.
+set(H5_STDC_HEADERS "On")
+
 add_subdirectory(vtkhdf5)
 
 foreach(lib