[Ada] Do not generate special PARM_DECL in LTO mode

[Eric Botcazou]

> Shouldn't it be simply the abstract origin for the VAR_DECL?  Or be
> not 'lowered'
> here but be a 'proper' PARM_DECL with DECL_VALUE_EXPR?  That said,
> how is debug info emitted in the optimize case?

This is a PARM_DECL with DECL_VALUE_EXPR set to the VAR_DECL emitted in the 
outermost function scope.  It doesn't survive with optimization enabled so we 
don't bother generating it in this case.

-- 
Eric Botcazou