stdlib_*laset add array bound checks in presence of hardcoded input address

[perazz]

Fix #835. Calls like this

call stdlib_slaset( 'U', nr-1,nr-1, zero,zero, a(1,2),lda )

cause bound checking errors in debug mode in case nr==1 because size(a,2)==1 (internally, nothing would be executed).

In several other places, LAPACK already had this fixed i.e., at:

                    ! zero out below r
                    if( n > 1 ) then
                       call stdlib_slaset( 'L', n-1, n-1, zero, zero, a( 2, 1 ),lda )
                    end if

i.e. by simply requiring n>1. This PR extends this safety checks to all applicable cases, i.e. where argument a address is hard-coded. A test is added too.

cc: @jvdp1 @jalvesz @loiseaujc @fortran-lang/stdlib

[jvdp1]

LGTM! Thank you @perazz

[perazz]

Thank you @jvdp1. Let's wait one or two days, and then merge if there are no further comments.