[Bug debug/99490] New: -gdwarf-5 -gsplit-dwarf puts .debug_rnglists to main file, not .dwo file

["jan.kratochvil at redhat dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99490

            Bug ID: 99490
           Summary: -gdwarf-5 -gsplit-dwarf puts .debug_rnglists to main
                    file, not .dwo file
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jan.kratochvil at redhat dot com
  Target Milestone: ---

FAIL: gcc-11.0.0-0.19.fc35.x86_64
PASS: clang-12.0.0-0.1.rc1.fc35.x86_64

double p_ext=3.14,e_ext=2.71;
int main(void) {
  double q,f;
  { volatile double p=p_ext;
    q=p/1.1;
  }
  { volatile double e=e_ext;
    f=e/1.1;
  }
  return q+f;
}

clang -o range-clang range.c -Wall -O3 -gdwarf-5 -gsplit-dwarf;gcc -o
range-gcc.s range.c -Wall -O3 -gdwarf-5 -gsplit-dwarf
llvm-readelf -WS range-{clang,gcc}{,.dwo} | egrep '^File:|debug_rnglists'
File: range-clang
File: range-clang.dwo
  [ 6] .debug_rnglists.dwo PROGBITS      0000000000000000 0001d4 000017 00   E 
0   0  1
Actual:
File: range-gcc
  [33] .debug_rnglists   PROGBITS        0000000000000000 004c0a 000049 00     
0   0  1
File: range-gcc.dwo
Expected:
File: range-gcc
File: range-gcc.dwo
  [33] .debug_rnglists   PROGBITS        0000000000000000 004c0a 000049 00     
0   0  1

DWARF-5 spec:
"The .debug_rnglists.dwosection contains range lists referenced by any
DW_AT_ranges attributes in the split DWARF object."
"Range lists are contained in a separate object file section called
.debug_rnglists or .debug_rnglists.dwo (in split units)."

Reproducer from attached .s files:
: clang -S -o range-clang.s range.c -Wall -O3 -gdwarf-5 -gsplit-dwarf;clang -o
range-clang range-clang.s -Wall -gdwarf-5 -gsplit-dwarf;: gcc -S -o range-gcc.s
range.c -Wall -O3 -gdwarf-5 -gsplit-dwarf;gcc -o range-gcc range-gcc.s -Wall
-gdwarf-5 -gsplit-dwarf