Fix ifx errors in legacy GOCART GridComps (Ops emissions)

[mathomp4]

Summary

Fixes #398

When running GEOSgcm v12 with ifx 2025.3 and OPS emissions in Release mode, the CO_GridComp (and other legacy GOCART GridComps) would fail during initialization due to ifx's stricter enforcement of intent(in) on arguments that are temporarily modified internally.

Changes

• Changed intent(in) to intent(inout) on w_c (Chem_Bundle) arguments in Aero, CFC, CH4, CO, CO2, and Rn GridComps, as sub-components temporarily modify registry indices during execution
• Initialize eCO_bioburn_ to 0.0 in CO_GridCompMod.F90 to prevent use of uninitialized data when diurnal_bb is false
• Guard DEALLOCATE of ier in CO_GridCompMod.F90 with an ALLOCATED check
• Add local ios variable in CO_Emission to prevent host-association aliasing under optimization

Testing

All tests with v12 show this is zero-diff for Ops runs.

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More info from Claude:

Root Cause

The real bug was intent(in) declared on w_c (type Chem_Bundle) in the outer public-facing routines (Initialize, Run, Finalize) across multiple species GridComps, while the *_SingleInstance_ wrapper routines declared it intent(inout) and actually modified w_c%reg%{n,i,j}_CO (and equivalent fields for other species).

This is a Fortran aliasing violation: passing an intent(in) actual argument to an intent(inout) dummy argument. ifx at optimization level is legally allowed to assume intent(in) variables cannot change across a call, so it cached w_c%reg%i_CO, w_c%reg%j_CO etc. in registers. The SingleInstance_ wrapper modifies these fields temporarily (saves, sets to single-instance values, calls method, restores), but the inner routine CO_GridCompInitialize1_ (etc.) read the stale cached values — causing nbeg /= nend → rc=1 → propagated up as rc=3001.

Failure trace decoded

• GOCART_GridCompMod.F90:1006 → Aero_GridCompInitialize → status=3001
• 3001 = 2000 (CO offset in Aero) + 1000 (instance wrapper offset) + 1 (nbeg /= nend check in CO_GridCompInitialize1_)

Why prints made it work

I/O flushes force register spills to memory, incidentally making the stale-cache issue disappear.