Print unknown constants using their values. This fixes #1047 but may be
reverted in #1811 to prefer declaring constants with names. However this
PR also adds support for `NaN` in C and an associated test. It also
removes the duplicate `_print_Constant` function.

---------

Co-authored-by: EmilyBourne <[email protected]>

Print unknown constants using their values. This fixes pyccel#1047 but may be
reverted in pyccel#1811 to prefer declaring constants with names. However this
PR also adds support for `NaN` in C and an associated test. It also
removes the duplicate `_print_Constant` function.

---------

Co-authored-by: EmilyBourne <[email protected]>

Print unknown constants using their values. This fixes #1047 but may be
reverted in #1811 to prefer declaring constants with names. However this
PR also adds support for `NaN` in C and an associated test. It also
removes the duplicate `_print_Constant` function.

---------

Co-authored-by: EmilyBourne <[email protected]>

Print unknown constants using their values. This fixes #1047 but may be
reverted in #1811 to prefer declaring constants with names. However this
PR also adds support for `NaN` in C and an associated test. It also
removes the duplicate `_print_Constant` function.

---------

Co-authored-by: EmilyBourne <[email protected]>

Print unknown constants using their values. This fixes #1047 but may be
reverted in #1811 to prefer declaring constants with names. However this
PR also adds support for `NaN` in C and an associated test. It also
removes the duplicate `_print_Constant` function.

---------

Co-authored-by: EmilyBourne <[email protected]>

Print all constant C variables with `const` specifier. This helps avoid
warnings in the wrapper stage (see #2200) and may help the compiler. It
may also be relevant for #1811 . Before this PR only arguments with a
`const` specifier were declared as const.

Print all constant C variables with `const` specifier. This helps avoid
warnings in the wrapper stage (see #2200) and may help the compiler. It
may also be relevant for #1811 . Before this PR only arguments with a
`const` specifier were declared as const.

When creating the release branch I noticed an import which was
accidentally deleted although it is used in the file. This PR puts it
back. The object is used here:
https://github.com/pyccel/pyccel/blob/devel/pyccel/codegen/printing/ccode.py#L2795

This is the fallback case for Constant which we do not use currently
(i.e. it is not currently tested). It will either be removed with
#1811 or will start being used and
tested