aa81e2c Enable UBSan for Travis fuzzer job (practicalswift)

Pull request description:

  Enable UBSan for Travis fuzzing job (`00_setup_env_amd64_fuzz.sh`).

ACKs for top commit:
  MarcoFalke:
    ACK aa81e2c

Tree-SHA512: 6c72df49db113b27e5ed5eb0fac69fa01dc36cccc802ac444349533747437a72cb5e073490e10de4a838f0ea202693e74c09d69061b9ee0f6d2129320ccb4bcd

Fixes bitcoin#17006 for both `bitcoind` and `bitcoin-qt`.

…se of uninitialized memory

870f0cd build: Add MemorySanitizer (MSan) in Travis to detect use of uninitialized memory (practicalswift)

Pull request description:

  Add MemorySanitizer (MSan) in Travis to detect use of uninitialized memory.

  First UBSan, then ASan followed by TSan... and now: yes, the wait is over -- **MSan is finally here!** :)

  Some historical context:
  * 2017: Continuous compilation with Clang Thread Safety analysis enabled (#10866, #10923)
  * 2018: Continuous testing with trapping on signed integer overflows (`-ftrapv`) (#12686)
  * 2018: Continuous testing of use of locale dependent functions (#13041)
  * 2018: Continuous testing of format strings (#13705)
  * 2018: Continuous compilation with MSVC `TreatWarningAsError` (#14151)
  * 2018: Continuous testing under UndefinedBehaviorSanitizer – UBSan (#14252, #14673, #17006)
  * 2018: Continuous testing under AddressSanitizer – ASan (#14794, #17205, #17674)
  * 2018: Continuous testing under ThreadSanitizer – TSan (#14829)
  * 2019: Continuous testing in an unsigned char environment (`-funsigned-char`) (#15134)
  * 2019: Continuous compile-time testing of assumptions we're making (#15391)
  * 2019: Continuous testing of fuzz test cases under Valgrind (#17633, #18159, #18166)
  * 2020: Finally... MemorySanitizer – MSAN! :)

  What is the next step? What tools should we add to CI to keep bugs from entering `master`? :)

ACKs for top commit:
  MarcoFalke:
    ACK 870f0cd

Tree-SHA512: 38327c8b75679d97d469fe42e704cacd1217447a5a603701dd8a58ee50b3be2c10248f8d68a479ed081c0c4b254589d3081c9183f991640b06ef689061f75578

…etect use of uninitialized memory

870f0cd build: Add MemorySanitizer (MSan) in Travis to detect use of uninitialized memory (practicalswift)

Pull request description:

  Add MemorySanitizer (MSan) in Travis to detect use of uninitialized memory.

  First UBSan, then ASan followed by TSan... and now: yes, the wait is over -- **MSan is finally here!** :)

  Some historical context:
  * 2017: Continuous compilation with Clang Thread Safety analysis enabled (bitcoin#10866, bitcoin#10923)
  * 2018: Continuous testing with trapping on signed integer overflows (`-ftrapv`) (bitcoin#12686)
  * 2018: Continuous testing of use of locale dependent functions (bitcoin#13041)
  * 2018: Continuous testing of format strings (bitcoin#13705)
  * 2018: Continuous compilation with MSVC `TreatWarningAsError` (bitcoin#14151)
  * 2018: Continuous testing under UndefinedBehaviorSanitizer – UBSan (bitcoin#14252, bitcoin#14673, bitcoin#17006)
  * 2018: Continuous testing under AddressSanitizer – ASan (bitcoin#14794, bitcoin#17205, bitcoin#17674)
  * 2018: Continuous testing under ThreadSanitizer – TSan (bitcoin#14829)
  * 2019: Continuous testing in an unsigned char environment (`-funsigned-char`) (bitcoin#15134)
  * 2019: Continuous compile-time testing of assumptions we're making (bitcoin#15391)
  * 2019: Continuous testing of fuzz test cases under Valgrind (bitcoin#17633, bitcoin#18159, bitcoin#18166)
  * 2020: Finally... MemorySanitizer – MSAN! :)

  What is the next step? What tools should we add to CI to keep bugs from entering `master`? :)

ACKs for top commit:
  MarcoFalke:
    ACK 870f0cd

Tree-SHA512: 38327c8b75679d97d469fe42e704cacd1217447a5a603701dd8a58ee50b3be2c10248f8d68a479ed081c0c4b254589d3081c9183f991640b06ef689061f75578