BUG: mips-unknown-elf assembly fails for lb macro

[Fred Fish]

The following code no longer assembles with the mips-unknown-elf
assembler:

        lb $3,0xB40000F0

The error is:

        $ ./as-new-bad y.s
        y.s: Assembler messages:
        y.s:1: Error: load/store address overflow (max 32 bits)

Older version assemble this into:

        0:   3c03b400        lui     v1,0xb400
        4:   806300f0        lb      v1,240(v1)

The problem seems to be this patch chunk in tc-mips.c:

        ***************
        *** 5894,5899 ****
        --- 6294,6303 ----
          
                      return;
                    }
        +         else if (offset_expr.X_op == O_constant
        +                  && !HAVE_64BIT_ADDRESS_CONSTANTS
        +                  && !IS_SEXT_32BIT_NUM (offset_expr.X_add_number))
        +           as_bad (_("load/store address overflow (max 32 bits)"));
          
                  if (breg == 0)
                    {

-Fred