Eliminate PL_sawalias, GPf_ALIASED_SV

These two commits:

    v5.21.3-759-gff2a62e "Skip no-common-vars optimisation for aliases"
    v5.21.4-210-gc997e36 "Make list assignment respect foreach aliasing"

added a run-time mechanism to detect aliased package variables,
by either "*pkg = ...," or "for $pkg (...)", and used that information
to enable the OPpASSIGN_COMMON mechanism at runtime for detecting common
elements in a list assign, e.g.

    for $alias ($a, ...) {
        ($a,$b) = (1,$alias);
    }

The previous commit but one changed the OPpASSIGN_COMMON mechanism such
that it no longer uses PL_sawalias. So this var and the mechanism for
setting it can now be removed.

This commit removes:

    * the PL_sawalias variable
    * the GPf_ALIASED_SV GP flag
    * the SAVEt_GP_ALIASED_SV and save_aliased_sv() save type.

1 files changed, 0 insertions, 1 deletions

diff --git a/embed.h b/embed.h
index c03c0f5fc6..0611ea9327 100644
--- a/embed.h
+++ b/embed.h
@@ -1304,7 +1304,6 @@
 #define rsignal_restore(a,b)	Perl_rsignal_restore(aTHX_ a,b)
 #define rsignal_save(a,b,c)	Perl_rsignal_save(aTHX_ a,b,c)
 #define rxres_save(a,b)		Perl_rxres_save(aTHX_ a,b)
-#define save_aliased_sv(a)	Perl_save_aliased_sv(aTHX_ a)
 #define save_strlen(a)		Perl_save_strlen(aTHX_ a)
 #define sawparens(a)		Perl_sawparens(aTHX_ a)
 #define scalar(a)		Perl_scalar(aTHX_ a)