Merge #20430: sanitizers: Add suppression for unsigned-integer-overflow in libstdc++

0f020cd sanitizers: Add suppression for unsigned-integer-overflow in libstdc++ basic_string.tcc (Jonas Schnelli)

Pull request description:

  Reported here: https://bitcoinbuilds.org/logs/e35cd579-0f0f-47e4-b49a-4ceba8ff9830.log
  Issue: https://github.com/gcc-mirror/gcc/blob/master/libstdc%2B%2B-v3/include/bits/basic_string.tcc#L1271

ACKs for top commit:
  MarcoFalke:
    cr ACK 0f020cd
  practicalswift:
    cr ACK 0f020cd

Tree-SHA512: e304259a1eed878263bd715b4d16c57f8974264c23ccd6799f85e8141b2eb0b5c6468a6452ffbc7334f57c1957b6e43bb248760b3c0718d93f092d57764d0a8f

Author: fanquake

test/sanitizer_suppressions/ubsan

@@ -6,6 +6,7 @@
 # contains files in which we expect unsigned integer overflows to occur. The
 # list is used to suppress -fsanitize=integer warnings when running our CI UBSan
 # job.
+unsigned-integer-overflow:*/include/c++/*/bits/basic_string.tcc
 unsigned-integer-overflow:arith_uint256.h
 unsigned-integer-overflow:basic_string.h
 unsigned-integer-overflow:bench/bench.h