Libtool currently assumes that certain characteristics, such as

Libtool currently assumes that certain characteristics, such as
enable_shared, apply to the host architecture rather than per-
language.  Running the tests over a broken compiler can corrupt
these values, when there is no C++ compiler for example, so we
skip most of the tests in those cases.

* m4/libtool.m4 (_LT_LANG_CXX_CONFIG): If caught_CXX_compiler was
set from configure.ac, then don't run all the compiler tests.
(_LT_LANG_F77_CONFIG): Similarly for caught_F77_compiler.