[Bug debug/99319] New: DW_MACRO_define_strp uses uleb128 for second operand

["vries at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99319

            Bug ID: 99319
           Summary: DW_MACRO_define_strp uses uleb128 for second operand
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vries at gcc dot gnu.org
  Target Milestone: ---

Consider compiling hello world, with macro info:
...
$ gcc-11 -ggdb3 -g hello.c -dA -save-temps
...

In a-hello.s, we have:
...
        .section        .debug_macro,"",@progbits
.Ldebug_macro0:
        .value  0x5     # DWARF macro version number
        .byte   0x2     # Flags: 32-bit, lineptr present
        .long   .Ldebug_line0
        .byte   0x3     # Start new file
        .uleb128 0      # Included from line number 0
        .uleb128 0x1    # file hello.c
        .byte   0x5     # Define macro strp
        .uleb128 0      # At line number 0
        .long   .LASF2  # The macro: "__STDC__ 1"
...

So, the DW_MACRO_define_strp entry (starting with .byte 0x5) has two operands,
a uleb128 and a .long.

AFAIU, this is in accordance with the spec:
...
A DW_MACRO_define_strp or DW_MACRO_undef_strp entry has two operands. The first
operand encodes the source line number of the #define or #undef macro
directive. The second operand consists of an offset into a string table
contained in the .debug_str section of the object file. The size of the operand
is given in the header offset_size_flag field.
...

Now add -gsplit-dwarf:
...
$ gcc-11 -ggdb3 -g hello.c -dA -save-temps -gsplit-dwarf
...

Now we have instead:
...
        .section        .debug_macro.dwo,"e",@progbits
.Ldebug_macro0:
        .value  0x5     # DWARF macro version number
        .byte   0x2     # Flags: 32-bit, lineptr present
        .long   .Lskeleton_debug_line0
        .byte   0x3     # Start new file
        .uleb128 0      # Included from line number 0
        .uleb128 0x1    # file hello.c
        .byte   0x5     # Define macro strp
        .uleb128 0      # At line number 0
        .uleb128 0x191  # The macro: "__STDC__ 1"
...

The second operand is now also a .uleb128.  AFAIU, this goes against the spec.