[PATCH] GAS: Replace macro LITERAL_PREFIXDOLLAR_HEX with a runtime value.

[Alan Modra]

This patch caused build failures on m68hc11, m68hc12 and m68k.
Please fix.  You also forgot to commit an entry in gas/ChangeLog.

/home/alan/src/binutils-gdb/gas/expr.c: In function ‘operand’:
/home/alan/src/binutils-gdb/gas/expr.c:1125:5: error: duplicate case value
 1125 |     case '$':
      |     ^~~~
/home/alan/src/binutils-gdb/gas/expr.c:783:5: note: previously used here
  783 |     case '$':
      |     ^~~~
Makefile:1224: recipe for target 'expr.o' failed

-- 
Alan Modra
Australia Development Lab, IBM