Dear all,

gfortran's ABI specifies that actual arguments to CHARACTER(LEN=1),VALUE
dummy arguments are passed by value in the scalar case.  That did work
for constant strings being passed, but not in several other cases, where
pointers were passed, resulting in subsequent random junk...

The attached patch fixes this for the case of a non-constant string
argument.

It does not touch the character,value bind(c) case - this is a different
thing and may need separate work, as Mikael pointed out - and there is
a missed optimization for the case of actual constant string arguments
of length larger than 1: it appears that the full string is pushed to
the stack.  I did not address that, as the primary aim here is to get
correctly working code.  (I added a TODO in a comment.)

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

Thanks,
Harald