Fix PAD weirdness

src/toolsrc/plforth.pla

@@ -15,7 +15,7 @@ byte  srclevel   = 0
 //
 // Internal buffers
 //
-word                      strbuf, padbuf
+word                      strbuf
 res[SRCREFS * INBUF_SIZE] inbuf
 res[t_except]             exitforth
 //
@@ -1165,7 +1165,7 @@ def _fill_(a,b,c)#0
   memset(a, c | (c << 8), b)
 end
 def _pad_#1
-  return padbuf
+  return heapmark + 512
 end
 def _trailing_(a,b)#2
   while b and ^(a + b - 1) == ' '
@@ -1972,7 +1972,6 @@ _estkl = ^(@syscall + 1) // Hack to fill in parameter stack locations
 _estkh = ^(@syscall + 3)
 fileio:iobufalloc(4) // Allocate a bunch of file buffers
 strbuf = heapalloc(256)
-padbuf = heapalloc(256)
 startheap = heapmark
 coldstart
 //