move total_ms, total_pixels out of zero page

this frees up 12 bytes of zero page space and costs no measurable
time as these variables are not in the hot path and there was only
a tiny bit different.

mandel.s

@@ -33,8 +33,7 @@ chroma_ticks    = $bd ; u8
 count_frames    = $be ; u8
 count_pixels    = $bf ; u8
 
-total_pixels    = $c0 ; float48
-total_ms        = $c6 ; float48
+; free space c0-cb
 temp            = $cc ; u16
 temp2           = $ce ; u16
 
@@ -63,6 +62,7 @@ FADD   = $DA66 ; ADDITION       (FR0 += FR1)
 FSUB   = $DA60 ; SUBTRACTION    (FR0 -= FR1)
 FMUL   = $DADB ; MULTIPLICATION (FR0 *= FR1)
 FDIV   = $DB28 ; DIVISION       (FR0 /= FR1)
+ZFR0   = $DA44 ; clear FR0
 ZF1    = $DA46 ; CLEAR ZERO PAGE FLOATING POINT NUMBER (XX)
 FLD0R  = $DD89 ; LOAD FR0 WITH FLOATING POINT NUMBER (YYXX)
 FLD1R  = $DD98 ; LOAD FR1 WITH FLOATING POINT NUMBER (YYXX)
@@ -203,6 +203,16 @@ ms_per_frame: ; float48 16.66666667
     .byte $66
     .byte $67
 
+total_pixels: ; float48
+    .repeat 6
+        .byte 0
+    .endrepeat
+
+total_ms: ; float48
+    .repeat 6
+        .byte 0
+    .endrepeat
+
 display_list_start:
     ; 24 lines overscan
     .repeat 3
@@ -1565,10 +1575,13 @@ main_loop:
     sta count_pixels
 
     ; total_ms = 0.0; total_pixels = 0.0
-    ldx #total_ms
-    jsr ZF1
-    ldx #total_pixels
-    jsr ZF1
+    jsr ZFR0
+    ldx #.lobyte(total_ms)
+    ldy #.hibyte(total_ms)
+    jsr FST0R
+    ldx #.lobyte(total_pixels)
+    ldy #.hibyte(total_pixels)
+    jsr FST0R
 
     jsr clear_screen
     jsr status_bar
@@ -1691,19 +1704,19 @@ update_status:
     jsr FMUL
 
     ; FR0 += total_ms
-    ldx #total_ms
-    ldy #0
+    ldx #.lobyte(total_ms)
+    ldy #.hibyte(total_ms)
     jsr FLD1R
     jsr FADD
 
     ; total_ms = FR0
-    ldx #total_ms
-    ldy #0
+    ldx #.lobyte(total_ms)
+    ldy #.hibyte(total_ms)
     jsr FST0R
 
     ; FR0 /= total_pixels
-    ldx #total_pixels
-    ldy #0
+    ldx #.lobyte(total_pixels)
+    ldy #.hibyte(total_pixels)
     jsr FLD1R
     jsr FDIV