libc: re-enable tests for strtoll, strtoull #3630

All 7 256 tests pass, 702 skipped in 40m 17s

7 958 tests +226 7 256 ✅ +247 40m 17s ⏱️ + 3m 21s
461 suites + 18 702 💤 + 3
1 files ± 0 0 ❌ - 24

Results for commit e926de2. ± Comparison against earlier commit 1759513.