[Bug bootstrap/69312] [6 Regression] libstdc++ unconditionally refers to TM symbols

[dje at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69312

--- Comment #2 from David Edelsohn <dje at gcc dot gnu.org> ---
stage1 libstdc++ builds, but stage2 configure fails because conftest programs
cannot link and run due to missing ITM_xxx symbols.