Added support to SBType for getting template arguments from a SBType:

uint32_t
SBType::GetNumberOfTemplateArguments ();

lldb::SBType
SBType::GetTemplateArgumentType (uint32_t idx);

lldb::TemplateArgumentKind
SBType::GetTemplateArgumentKind (uint32_t idx);

Some lldb::TemplateArgumentKind values don't have a corresponding SBType
that will be returned from SBType::GetTemplateArgumentType(). This will
help our data formatters do their job by being able to find out the
type of template params and do smart things with those.

llvm-svn: 149658