Merge #16117: util: Replace boost sleep with std sleep

fae86c38bc util: Remove unused MilliSleep (MarcoFalke)
fa9af06d91 scripted-diff: Replace MilliSleep with UninterruptibleSleep (MarcoFalke)
fa4620be78 util: Add UnintrruptibleSleep (MarcoFalke)

Pull request description:

  We don't use the interruptible feature of boost's sleep anywhere, so replace it with the sleep in `std::thread`

ACKs for top commit:
  ajtowns:
    ACK fae86c38bc quick code review
  practicalswift:
    ACK fae86c38bc -- patch looks correct
  sipa:
    Concept and code review ACK fae86c38bc
  fanquake:
    ACK fae86c38bc - note that an instance of `DHAVE_WORKING_BOOST_SLEEP_FOR` was missed in the [linter](https://github.com/bitcoin/bitcoin/blob/master/test/lint/extended-lint-cppcheck.sh#L69), but that can be cleaned up later.

Tree-SHA512: 7c0f8eb197664b9f7d9fe6c472c77d384f11c797c913afc31de4b532e3b4fd9ea6dd174f92062ff9d1ec39b25e0900ca7c597435add87f0f2477d9557204848c

src/util/time.cpp

@@ -11,10 +11,13 @@
 
 #include <atomic>
 #include <boost/date_time/posix_time/posix_time.hpp>
-#include <boost/thread.hpp>
 #include <ctime>
+#include <thread>
+
 #include <tinyformat.h>
 
+void UninterruptibleSleep(const std::chrono::microseconds& n) { std::this_thread::sleep_for(n); }
+
 static std::atomic<int64_t> nMockTime(0); //!< For unit testing
 
 int64_t GetTime()
@@ -72,24 +75,6 @@ int64_t GetSystemTimeInSeconds()
     return GetTimeMicros()/1000000;
 }
 
-void MilliSleep(int64_t n)
-{
-
-/**
- * Boost's sleep_for was uninterruptible when backed by nanosleep from 1.50
- * until fixed in 1.52. Use the deprecated sleep method for the broken case.
- * See: https://svn.boost.org/trac/boost/ticket/7238
- */
-#if defined(HAVE_WORKING_BOOST_SLEEP_FOR)
-    boost::this_thread::sleep_for(boost::chrono::milliseconds(n));
-#elif defined(HAVE_WORKING_BOOST_SLEEP)
-    boost::this_thread::sleep(boost::posix_time::milliseconds(n));
-#else
-//should never get here
-#error missing boost sleep implementation
-#endif
-}
-
 std::string FormatISO8601DateTime(int64_t nTime) {
     struct tm ts;
     time_t time_val = nTime;