merge revision(s) 63711,64398: [Backport #14841]

	thread_sync.c (rb_mutex_lock): fix deadlock

	* thread_sync.c (rb_mutex_lock): fix deadlock
	  [ruby-core:87467] [Bug #14841]

	thread_sync.c (rb_mutex_lock): acquire lock before being killed

	We (the thread acquiring the mutex) need to acquire the mutex
	before being killed to work with ConditionVariable#wait.

	Thus we reinstate the acquire-immediately-after-sleeping logic
	from pre-r63711 while still retaining the
	acquire-after-checking-for-interrupts logic from r63711.

	This regression was introduced in
	commit 501069b (r63711)
	("thread_sync.c (rb_mutex_lock): fix deadlock") for
	[Bug #14841]

	[ruby-core:88503] [Bug #14999] [Bug #14841]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@65115 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

thread_sync.c

@@ -299,7 +299,11 @@ rb_mutex_lock(VALUE self)
 	    if (mutex->th == th) mutex_locked(th, self);
 
 	    if (interrupted) {
-		RUBY_VM_CHECK_INTS_BLOCKING(th);
+		RUBY_VM_CHECK_INTS_BLOCKING(th); /* may release mutex */
+		if (!mutex->th) {
+		    mutex->th = th;
+		    mutex_locked(th, self);
+		}
 	    }
 	}
     }

version.h

@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.4.5"
 #define RUBY_RELEASE_DATE "2018-10-17"
-#define RUBY_PATCHLEVEL 329
+#define RUBY_PATCHLEVEL 330
 
 #define RUBY_RELEASE_YEAR 2018
 #define RUBY_RELEASE_MONTH 10