GECON returns 1 if RCOND is NaN

[weslleyspereira]

This is aligned to the behavior in the routines that compute norms, i.e., to propagate NaNs instead of calling XERBLA.

This PR also solves the issue about INFO returning zero when RCOND=NAN. This PR makes GECON return 1 if RCOND=NAN. The return INFO=1 is aligned to what we propose in the exception handling for LAPACK at https://arxiv.org/pdf/2207.09281.pdf

Complete behavior for INFO:

*> \param[out] INFO
*> \verbatim
*>          INFO is INTEGER
*>          = 0:  successful exit
*>          < 0:  if INFO = -i, the i-th argument had an illegal value.
*>                NaNs are illegal values for ANORM, and they propagate to
*>                the output parameter RCOND.
*>                Infinity is illegal for ANORM, and it propagates to the output
*>                parameter RCOND as 0.
*>          = 1:  if RCOND = NaN, or
*>                   RCOND = Inf, or
*>                   the computed norm of the inverse of A is 0.
*>                In the latter, RCOND = 0 is returned.
*> \endverbatim

Related to #763.

[codecov]

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Additional details and impacted files

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Files	Coverage Δ
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SRC/dorbdb6.f	0.00% <ø> (ø)
SRC/sorbdb6.f	0.00% <ø> (ø)
SRC/zunbdb6.f	0.00% <ø> (ø)
SRC/cbdsqr.f	0.00% <0.00%> (ø)
SRC/zbdsqr.f	0.00% <0.00%> (ø)
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SRC/dgecon.f	0.00% <0.00%> (ø)
SRC/sgecon.f	0.00% <0.00%> (ø)
SRC/zgecon.f	0.00% <0.00%> (ø)

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