scripts: Add "|" operator support to glibcpp's parsing

scripts: Add "|" operator support to glibcpp's parsing

From the tests point of view, this is a necessary step for another
patch [1] and allows parsing macros such as "#define A | B".  Without
it, a few tests [2] choke when the other patch [1] is applied:

/src/glibc/scripts/../elf/elf.h:4167: error: uninterpretable macro
token sequence: ( EF_ARC_MACH_MSK | EF_ARC_OSABI_MSK )
Traceback (most recent call last):
    File "/src/glibc/elf/tst-glibcelf.py", line 23, in <module>
      import glibcelf
    File "/src/glibc/scripts/glibcelf.py", line 226, in <module>
      _elf_h = _parse_elf_h()
               ^^^^^^^^^^^^^^
    File "/src/glibc/scripts/glibcelf.py", line 223, in _parse_elf_h
      raise IOError('parse error in elf.h')
  OSError: parse error in elf.h

[1] ARC: update definitions in elf/elf.h
https://sourceware.org/pipermail/libc-alpha/2022-November/143503.html

[2]
tst-glibcelf, tst-relro-ldso, and tst-relro-libc

Reviewed-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Shahab Vahedi <shahab@synopsys.com>