[Bug bootstrap/65763] tm.h: No such file or directory

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65763

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
$ ./configure --prefix=/opt/gcc-5.1 --enable-languages=c,c++ --enable-lto

please do not configure in the source directory but use a separate build
directory.