[PATCH v1] libstdc++-v3: Update VTV vars for libtool link commands [PR99172]

[Jonathan Wakely]

On 11/03/21 16:27 +0000, Jonathan Wakely wrote:
>That seems cleaner to me, rather than adding another variable with
>minor differences from the existing AM_CXXFLAGS.

My specific concern is that AM_CXXFLAGS and AM_CXXFLAGS_LT will get
out of sync, i.e. we'll add something to the former and forget to add
it to the latter.

If we keep using AM_CXXFLAGS but cancel out the -fvtable-verify=std
option, then there aren't two separate variables that can diverge.

But I think it's too late in the gcc-11 process for that kind of
refactoring.