fa69ac7 doxygen: Fix member comments (MarcoFalke)

Pull request description:

  Trailing comments must be indicted with the caret `//!<`.

  Not all places do this right now, see for example https://dev.visucore.com/bitcoin/doxygen/txmempool_8h.html#a2bc6653552b5871101b6cbefdbaf251f, but they can be fixed with an almost-scripted-diff:

  ```
  sed -i --regexp-extended -e 's/((,|;) *\/\/!) /\1< /g' $(git grep --extended-regexp -l  '(,|;)\s*//!\s')
  ```

  (Same as  [doxygen] Fix member comments bitcoin#7793)

Tree-SHA512: 451077008353ccc6fcc795f34094b2d022feb7a171b562a07ba4de0dcb0aebc137e12b03970764bd81e2da386751d042903db4c4831900f43c0cfde804c81b2b

… the undefined behaviour sanitizer (UBSan)

9f49db7 Enable functional tests in UBSAN job. Enable -fsanitize=integer (part of UBSAN). Merge UBSAN Travis job with no depends. (practicalswift)

Pull request description:

  Run functional tests and benchmarks under the undefined behaviour sanitizer (UBSan).

  This will make Travis automatically detect issues such as:
  * bitcoin#14242: Avoid triggering undefined behaviour (`std::memset(nullptr, 0, 0)`) if an invalid string is passed to `DecodeSecret(...)`
  * bitcoin#14239: Avoid dividing by zero (undefined behaviour) in `EstimateMedianVal` (policy)/`ConnectTip` (validation)/`CreateTransaction` (wallet)
  * bitcoin#13546: wallet: Avoid potential use of uninitialized value `bnb_used` in `CWallet::CreateTransaction(...)`

  Addresses issue bitcoin#14059.

Tree-SHA512: 285e1542b36c582516c47938ce8d999fd89ba6c867bc0976e7306e7c949b8b84ffbfa43dbc679dd97ae639b086092e7d799d8e1c903c66a37d529ce61d5c64b4

continued 14252

Co-authored-by: UdjinM6 <[email protected]>

…ewly introduced UBSan errors

4773fa8 Add llvm-symbolizer directory to PATH. Needed to get symbolized stack traces from the sanitizers. (practicalswift)
5c292da Add UBSan suppressions needed to pass test suite (practicalswift)
fced6b5 Add UBSan options: print_stacktrace + halt_on_error (practicalswift)

Pull request description:

  Fail the UBSan Travis build in case of newly introduced [UBSan (UndefinedBehaviorSanitizer)](https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html) errors.

  Prior to this commit new UBSan errors were printed but didn't fail the UBSan Travis build.

  Changes:
  * Travis: Add UBSan options: `print_stacktrace` + `halt_on_error`
  * Travis: Add UBSan suppressions needed to pass test suite
  * Travis: Add `llvm-symbolizer` directory to PATH. Needed to get symbolized stack traces from the sanitizers.

  `halt_on_error` should have been part of bitcoin#14252 really :-)

Tree-SHA512: 30e960659196873d4f636f3a61267b8b4441a0e8773e3f3ae4660a9341d028c363636f0cb919ef9d6662ceb484e3d58054adfb6dc76ff8a355a1c9f927c328d1

fa7d36b test: Move UBSAN suppressions to test/sanitizer_suppressions/ubsan (MarcoFalke)
fa36d4e travis: --disable-hardening for xenial thread sanitizer (MarcoFalke)
89bf196 travis: Run thread sanitizer (MarcoFalke)

Pull request description:

  On unit tests only for now. Disabled for the gui unit tests and all functional tests.

Tree-SHA512: 56f7d3b44e7cb68c76a2dc5abd85658955b1c2188932e988667c5a1cbcdd6be995d37bb949d62c6eb08a4aebfc43ff0370b7da1719d4e4f322a3495c1941a5e0

Signed-off-by: pasta <[email protected]>