MAINT-1175: Forbid LLRegistry[Singleton]<std::type_info*, ...>.

Back out code that selects LLTypeInfoLookup for the underlying map
implementation when KEY = [const] std::type_info*, because LLTypeInfoLookup's
API is changing to become incompatible with std::map. Instead, fail with
STATIC_ASSERT when LLRegistry's KEY is [const] std::type_info*.
Fix all existing uses to use std::type_info::name() string instead.