Adapt the generating and dumping of object files to what is observed

in RSX-11M+ files. Use conditional compilation so the RT-11 version can
be restored.

object.c

@@ -55,6 +55,10 @@ DAMAGE.
   Each is preceeded by any number of 0 bytes, begins with a 1,0 pair,
   followed by 2 byte length, followed by data, followed by 1 byte
   negative checksum.
+
+  The RSX version is similar but subtly different:
+  There are no "any number of 0 bytes", nor the "1,0 pair" following it.
+  There is no checksum byte, but odd lengths are padded with a 0-byte.
 */
 
 static int writerec(
@@ -65,18 +69,24 @@ static int writerec(
     int             chksum;     /* Checksum is negative sum of all
                                    bytes including header and length */
     int             i;
+#if RT11
     unsigned        hdrlen = len + 4;
+#else
+    unsigned        hdrlen = len;
+#endif
 
     if (fp == NULL)
         return 1;                      /* Silently ignore this attempt to write. */
 
     chksum = 0;
+#if RT11
     if (fputc(FBR_LEAD1, fp) == EOF)   /* All recs begin with 1,0 */
         return 0;
     chksum -= FBR_LEAD1;
     if (fputc(FBR_LEAD2, fp) == EOF)
         return 0;
     chksum -= FBR_LEAD2;
+#endif /* RT11 */
 
     i = hdrlen & 0xff;                 /* length, lsb */
     chksum -= i;
@@ -99,7 +109,13 @@ static int writerec(
 
     chksum &= 0xff;
 
+#if RT11
     fputc(chksum, fp);                 /* Followed by the checksum byte */
+#else /* RT11 */
+    if (hdrlen & 1) {
+        fputc(0, fp);                  /* Padding to even boundary */
+    }
+#endif /* RT11 */
 
     return 1;                          /* Worked okay. */
 }