z80: remove popRS from stable ABI

blk/283

@@ -2,7 +2,7 @@ H@ ORG !
 0 JP, ( 00, main ) NOP, ( unused ) NOP, NOP, ( 04, BOOT )
 NOP, NOP, ( 06, uflw ) NOP, NOP, ( 08, LATEST ) NOP, ( unused )
 0 A, 0 JP, ( 0b, EXIT ) NOP, ( unused )
-0 JP, ( RST 10 )  NOP, ( unused ) 0 JP, ( 14, popRS )
+0 JP, ( RST 10 )  NOP, NOP, NOP, NOP, ( unused )
 NOP, NOP, NOP, ( unused )
 0 JP, ( 1a, next ) NOP, NOP, NOP, ( unused )
 0 JP, ( RST 20 )

blk/297

@@ -4,7 +4,7 @@ lblpushRS BSET
     1 IX+ H LDIXYr,
     RET,
 
-lblpopRS BSET PC ORG @ 0x15 + ! ( popRS )
+lblpopRS BSET
     L 0 IX+ LDrIXY,
     H 1 IX+ LDrIXY,
     IX DECd, IX DECd,

blk/305

@@ -6,6 +6,6 @@ CODE EXECUTE
 
 CODE EXIT
 PC ORG @ 0x0d + ! ( stable ABI JP )
-    0x14 BCALL,      ( popRS )
+    lblpopRS @ CALL,
     HL PUSH, IY POP, ( --> IP )
     JPNEXT,