[Bug c++/126754] [16/17 Regression] ICE in tsubst_expr, at cp/pt.cc:23354 since r16-5970

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126754

--- Comment #5 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Jason Merrill <[email protected]>:

https://gcc.gnu.org/g:654eb1f70643a2c57b3c6a31c250c1213a23aa4f

commit r17-3291-g654eb1f70643a2c57b3c6a31c250c1213a23aa4f
Author: Jason Merrill <[email protected]>
Date:   Tue Aug 11 16:12:10 2026 -0400

    c++: constexpr class access in generic lambda [PR126754]

    We don't want to see TARGET_EXPR in template trees because it's an
    implementation detail, not a representation of the source.  But constant
    evaluation normally represents a constant class value with a TARGET_EXPR.
    Let's not do the latter in a template.

            PR c++/126754

    gcc/cp/ChangeLog:

            * constexpr.cc (cxx_eval_outermost_constant_expr): Don't
            wrap in TARGET_EXPR when processing_template_decl.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp1y/constexpr-lambda2.C: New test.