[MC-142690] Server can get stuck while teleporting between dimensions

The bug

While teleporting between dimensions using /execute in <dimension> run teleport @s (or similar) the client got stuck at the "Loading terrain..." screen when I teleported from the overworld to the nether (previous teleports were successful). However it remained responsive.

It appears the underlying problem is that the server got stuck while performing the command (see attached jstack outputs):

19w03c

at java.lang.Thread.yield(Native Method)
at uq.b(SourceFile:147)
at uq.a(SourceFile:131)
at bci.a(SourceFile:260)
at bcm.a(SourceFile:120)
at bci.c(SourceFile:255)
at bci.a(SourceFile:590)
at ur.a(SourceFile:570)
at ut.a(SourceFile:1269)
at td.a(SourceFile:164)
at td.a(SourceFile:138)
at td.h(SourceFile:51)
at td$$Lambda$1917/813607430.run(Unknown Source)
at com.mojang.brigadier.CommandDispatcher.execute(CommandDispatcher.java:132)
at com.mojang.brigadier.CommandDispatcher.execute(CommandDispatcher.java:72)
at cb.a(SourceFile:223)
at vl.c(SourceFile:1088)
at vl.a(SourceFile:1075)
at ng.a(SourceFile:37)
at ng.a(SourceFile:9)
at jr.a(SourceFile:15)
at jr$$Lambda$2295/174447671.run(Unknown Source)
at qs.run(SourceFile:18)
at net.minecraft.server.MinecraftServer.p(SourceFile:694)
at net.minecraft.server.MinecraftServer.o(SourceFile:665)
at net.minecraft.server.MinecraftServer.run(SourceFile:624)
at java.lang.Thread.run(Thread.java:745)

The following might have been logged after using the command, though I am not completely sure and it might be the log messages of a previous teleport:

01:04:52	net.minecraft.server.MinecraftServer	[Marcono1234: Teleported Marcono1234 to Marcono1234]
01:04:52	drn	Saving and pausing game...
01:04:52	crd	[CHAT] Teleported Marcono1234 to Marcono1234
01:04:52	net.minecraft.server.MinecraftServer	Saving chunks for level '1.14 test'/minecraft:the_nether
01:04:52	bsu	ThreadedAnvilChunkStorage (DIM-1): All chunks are saved
01:04:52	net.minecraft.server.MinecraftServer	Saving chunks for level '1.14 test'/minecraft:overworld
01:04:52	bsu	ThreadedAnvilChunkStorage (1_14 test): All chunks are saved
01:04:52	net.minecraft.server.MinecraftServer	Saving chunks for level '1.14 test'/minecraft:the_end
01:04:52	bsu	ThreadedAnvilChunkStorage (DIM1): All chunks are saved

Forcing a crash failed, the client became unresponsive after logging "[CHAT] [Debug]: Crashing in 1...". The thread dump for this is force-crash-hang.txt.