[clang][TypePrinter] Teach isSubstitutedDefaultArgument about integral types

[clang][TypePrinter] Teach isSubstitutedDefaultArgument about integral types

This patch handles default integral non-type template parameters.

After this patch the clang TypePrinter will omit default integral
template arguments when the `PrintingPolicy::SuppressDefaultTemplateArgs`
option is specified and sets us up to be able to re-use
`clang::isSubstitutedDefaultArgument` from the DWARF CodeGen
component.

Differential Revision: https://reviews.llvm.org/D139986