CTF,BTF testsuite: Use -gdwarf-4 for restrict type qualifier [PR101283]

CTF,BTF testsuite: Use -gdwarf-4 for restrict type qualifier [PR101283]

DWARF DIEs do not contain DW_TAG_restrict_type when DWARF version is 2. CTF/BTF
generation feeds off DWARF DIEs, and as such, CTF records of kind
CTF_K_RESTRICT cease to be generated when DWARF version is 2.

This patch fixes the failure of these testcases on Darwin by using an explicit
-gdwarf-4 in the dg-options. This keeps the CTF record generation for restrict
type qualifier tested.

  PR debug/101283 - Several tests fail on Darwin with -gctf/gbtf

2021-07-05  Indu Bhagat  <indu.bhagat@oracle.com>

gcc/testsuite/ChangeLog:

	PR debug/101283
	* gcc.dg/debug/btf/btf-cvr-quals-1.c: Use -gdwarf-4 on Darwin targets.
	* gcc.dg/debug/ctf/ctf-cvr-quals-1.c: Likewise.