Rm Perl_newHV() from mathoms

This function can be converted to call plain newHV  without changing its
behavior.  I verified this by eyeballing its implementation in mathoms.c
and comparing that with what happens with just the plain macro.

That means embed.fnc can be changed to generate the Perl_ form
automatically, and the mathoms function can be removed.

Author: khwilliamson

embed.fnc

@@ -2205,7 +2205,7 @@ ARdp	|OP *	|newGVOP	|I32 type				\
 				|NN GV *gv
 ARdp	|OP *	|newGVREF	|I32 type				\
 				|NULLOK OP *o
-AMRbdp	|HV *	|newHV
+ARdmp	|HV *	|newHV
 ARdp	|HV *	|newHVhv	|NULLOK HV *hv
 ARdp	|OP *	|newHVREF	|NN OP *o
 ARdmp	|IO *	|newIO

embed.h

@@ -2292,6 +2292,7 @@
 #   define Perl_hv_store_ent(mTHX,a,b,c,d)      hv_store_ent(a,b,c,d)
 #   define Perl_hv_store_flags(mTHX,a,b,c,d,e,f) hv_store_flags(a,b,c,d,e,f)
 #   define Perl_newAV(mTHX)                     newAV()
+#   define Perl_newHV(mTHX)                     newHV()
 #   define Perl_newIO(mTHX)                     newIO()
 #   define Perl_newSUB(mTHX,a,b,c,d)            newSUB(a,b,c,d)
 #   define Perl_newSVsv(mTHX,a)                 newSVsv(a)
@@ -2353,6 +2354,7 @@
 #   define Perl_hv_store_ent                    hv_store_ent
 #   define Perl_hv_store_flags                  hv_store_flags
 #   define Perl_newAV                           newAV
+#   define Perl_newHV                           newHV
 #   define Perl_newIO                           newIO
 #   define Perl_newSUB                          newSUB
 #   define Perl_newSVsv                         newSVsv

mathoms.c

@@ -181,15 +181,6 @@ Perl_sv_nounlocking(pTHX_ SV *sv)
     PERL_UNUSED_ARG(sv);
 }
 
-HV *
-Perl_newHV(pTHX)
-{
-    HV * const hv = MUTABLE_HV(newSV_type(SVt_PVHV));
-    assert(!SvOK(hv));
-
-    return hv;
-}
-
 /*
 =for apidoc_section $unicode
 =for apidoc utf8_to_uvuni