ldbl-128ibm-compat: fixup subdir location of several funcs

We want to ensure that if a second file is built to support
ieee128 long double, we built its companion implementation
with ibm128 long double.  The shared object versions of these
files build correctly because the aliasing is sufficiently
complex to prevent the redirects from applying when defining
them.

However, this does not prevent the static object variants
from becoming quietly broken due to redirects.  This is
intentionally avoided by marking such objects to be built
with -mabi=ibmlongdouble.

Shuffle the misplaced routines to build against the subdir
which defines the needed symbols.