Improved error message for unhandled CIL type prints.
Improved error message for unhandled CIL type prints.

mono/CppSharp,ddobrev/CppSharp,inordertotest/CppSharp,ddobrev/CppSharp,u255436/CppSharp,u255436/CppSharp,inordertotest/CppSharp,ktopouzi/CppSharp,mono/CppSharp,u255436/CppSharp,mohtamohit/CppSharp,zillemarco/CppSharp,ddobrev/CppSharp,mono/CppSharp,ddobrev/CppSharp,mohtamohit/CppSharp,genuinelucifer/CppSharp,mohtamohit/CppSharp,genuinelucifer/CppSharp,u255436/CppSharp,ktopouzi/CppSharp,zillemarco/CppSharp,mono/CppSharp,inordertotest/CppSharp,mono/CppSharp,genuinelucifer/CppSharp,ktopouzi/CppSharp,ktopouzi/CppSharp,zillemarco/CppSharp,ddobrev/CppSharp,mohtamohit/CppSharp,zillemarco/CppSharp,genuinelucifer/CppSharp,inordertotest/CppSharp,inordertotest/CppSharp,mono/CppSharp,mohtamohit/CppSharp,ktopouzi/CppSharp,zillemarco/CppSharp,u255436/CppSharp,genuinelucifer/CppSharp