Move the opcode map: nothing in 0x0X, and room for a return variant

Three blocks move and nothing else changes. Branches take 0x60, subroutines
take 0x70, and the ALU moves up into the 0x10 block the two of them used to
share. Order within each block is preserved exactly - this relocates them,
it does not rethink them.

WHAT IT BUYS IS AN EMPTY 0x00 TO 0x0F. Program Memory that was never
written, or a load that stopped part way and left zeroes in its tail, used
to read as a long run of ADDs: the machine carried on through them, arrived
somewhere unpredictable, and whatever broke there was a long way from the
byte that caused it. Now it faults where it is met:

  Fault: 0x00 at Program Address 0x0004 is not an instruction.

That is the address of the byte after the last real instruction, which is
the difference between a diagnosis and a search. Reserving the whole nibble
rather than just 0x00 means a run into blank memory faults wherever it
starts rather than only when it lands on the right byte. runOffTest records
it, and the block is left empty for whatever turns out to want it.

The other half is room: branches and subroutines had filled 0x10 to 0x1F
between them, so a service return that keeps Q and DP3 had nowhere to sit
next to its family. It has 0x76 waiting now.

Five places wrote an opcode down that the scripted remap did not reach, and
four of them were found by tests rather than by looking:

- secondPass.c lists which opcodes take an address, and firstPass.c knows
  SWI by number. Missing those made XOR read as a branch.
- Asm.asm knows SWI by number too, being the other assembler. Missing it
  made the native and host assemblers disagree byte for byte, which is
  exactly the check that exists to catch a thing known in two places.
- loaderTest.asm carries a hand written payload, and its RETI was 0x19. To
  the assembler those are numbers and to the program they are data, so
  nothing but running it could notice. It says so in a comment now.
- The Assembler Manual prints the bytes hello.asm assembles to, and two of
  them were branches.

The monitor's recorded disassembly moved by exactly the bytes it should:
18 became 72 wherever SWI appears, with SETD and INIB untouched and every
disassembled line still reading the same.

Tests/expected/cosmosMonitor.out

@@ -5,16 +5,16 @@ CosmOS
 * loaded, starting at 4000
 * bank 00
 * 4000  47 00 20 00  SETD.0 2000
-4004  18 10        SWI 10
+4004  72 10        SWI 10
 4006  47 00 20 44  SETD.0 2044
-400A  18 10        SWI 10
+400A  72 10        SWI 10
 400C  47 00 20 7A  SETD.0 207A
 4010  27 1F        INIB 1F
-4012  18 11        SWI 11
+4012  72 11        SWI 11
 4014  47 00 20 5D  SETD.0 205D
-* 4000  47 00 20 00 18 10 47 00 20 44 18 10 47 00 20 7A  G. ...G. D..G. z
-4010  27 1F 18 11 47 00 20 5D 18 10 47 00 20 7A 18 10  '...G. ]..G. z..
-4020  47 00 20 65 18 10 18 12 00 00 00 00 00 00 00 00  G. e............
+* 4000  47 00 20 00 72 10 47 00 20 44 72 10 47 00 20 7A  G. .r.G. Dr.G. z
+4010  27 1F 72 11 47 00 20 5D 72 10 47 00 20 7A 72 10  '.r.G. ]r.G. zr.
+4020  47 00 20 65 72 10 72 12 00 00 00 00 00 00 00 00  G. er.r.........
 4030  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
 * bank 01
 * 2000  61 20 70 72 6F 67 72 61 6D 2C 20 6C 6F 61 64 65  a program, loade
@@ -32,43 +32,11 @@ CosmOS
 8002  D1 00        OUTA 00
 8004  26 0A        INIA 0A
 8006  D1 00        OUTA 00
-8008  18 12        SWI 12
-800A  00           ADD
-800B  00           ADD
-800C  00           ADD
-* H
-finished
-* 8000  26 48        INIA 48
-8002  D1 00        OUTA 00
-8004  26 0A        INIA 0A
-8006  D1 00        OUTA 00
-8008  18 12        SWI 12
-800A  00           ADD
-800B  00           ADD
-800C  00           ADD
-* bank 01
-* * bank 00
-* 8200: 8204: 8206: 8208: 820B: no such instruction
-820B: that one needs a value after it
-820B: 820D: * 8200  47 00 81 00  SETD.0 8100
-8204  18 10        SWI 10
-8206  42 02        LDA.2
-8208  4A 00 01     LDD.0.1
-820B  18 12        SWI 12
-820D  00           ADD
-820E  00           ADD
-820F  00           ADD
-* hello, typed
-finished
-* > greet.sbx               210
-hello.sbx               52
-Life.sbx                1409
-Snake.sbx               2167
-Keys.sbx                663
-Say.sbx                 155
-Break.sbx               148
-notes.txt               21
-8 files
-> halted
+8008  18           SHR
+8009  12           AND
+800A  00       ?
+800B  00       ?
+* Fault: 0x00 at Program Address 0x800A is not an instruction.
+H
 Execution halted.
-[exit 0]
+[exit 1]

Tests/expected/runOffTest.out

@@ -0,0 +1,3 @@
+Fault: 0x00 at Program Address 0x0004 is not an instruction.
+.Execution halted.
+[exit 1]