[imcc] add imcc flags to the refactored API and use it in parrot_old (again)

parrot_old -y works fine now.
Also re-enable symbolic api_flags by including the relevant headers.
Issue [GH #1033]

Add old imcc optim flags as Parrot_trace_flags, but the optimizations
are not yet passed through
[imcc] add more flags to parrot: -y -E -a

re-enable some old flags now in parrot2 also [GH #1033].
Also re-enable symbolic api_flags by including the relevant headers.
[GH #1035] require -a parrot arg for .pasm files

add -a to all .pasm file invocations, as temporary parrot
does not accept .pasm without -a set.
relax mandatory parrot -a requirement

check each argument for .pasm as in parrot_old, and set the
have_pasm_file flag (i.e. -a) then automatically.

broke t/pmc/sub.t and t/src/checkdepend.t
add new parrot.h deps for checkdepend.t

The 2 frontends include now all parrot.h headers,
not just a subset.
[docs] improve checkdepend.t SYNOPSIS
[docs] parrot* -h: replace runcore gcdebug by subprof
[imcc] add imcc_debug flags to Parrot_debug_flags, docs

revamp --imcc-debug, improve --help-debug
remove gcdebug runcore references in the docs
remove run-exec references in harness
leave out the imcc PBC compiler options (unused)

TODO: yydebug == PARROT_IMCC_PARSER
[imcc] merge yydebug with imccflags, init pasm and pir compilers

we need to init both compilers to fix t/pmc/sub.t
simplify imcc_set_debug_api: only take imccflags, and also call imcc_set_verbosity on -v
shift public PARROT_IMCC_* flags by 16 to private imcc->debug
enable -v (imcc->verbose)
use PARROT_IMCC_PARSER for imcc yydebug flag

TODO: imccflags do not yet arrive in imcc