As reported in PR48177, the type-deduction extraction ends up going into
an infinite loop when the type referred to has a recursive definition.
This stops recursing and just substitutes the type-source-info the
TypeLocBuilder identified when transforming the base.
The outputs between the direct ast-dump test and the ast-dump test after
deserialization should match modulo a few differences.
For hand-written tests, strip the "<undeserialized declarations>"s and
the "imported"s with sed.
For tests generated with "make-ast-dump-check.sh", regenerate the output.
Part 3/n.
As reported in PR46111, implicit instantiation of a deduction guide
causes us to have an elaborated type as the parameter, rather than the
dependent type.
After review and feedback from @rsmith, this patch solves this problem
by wrapping the value in an uninstantiated typedef/type-alias that is
instantiated when required later.
Differential Revision: https://reviews.llvm.org/D80743
Erich Keane