Dear Fortranners,

this one was really bugging me for quite some time.  We failed to
properly handle (= simplify) expressions using array constructors
with typespec, and with parentheses and unary '+' and '-'
sprinkled here and there.  When there was no typespec, there was
no related problem.

The underlying issue apparently was that we should simplify
elements of the array constructor before attempting the type
conversion.

Thanks to Gerhard, who insisted by submitted many related PRs.

Regtested on x86_64-pc-linux-gnu.  OK for mainline?

Thanks,
Harald