[MC-210622] Crash when firing a flint and steel down from a dispenser

Placing a fire block into an air block using flint and steel in a dispenser starts the "look for portal creation" process.

if you do that, with a dispenser looking down, the server/game crashes.

papers fix is here: https://github.com/PaperMC/Paper/commit/428db483a7af6978f90cfa952514798fb9847a05

(BlockFireAbstract = BaseFireBlock, in method isPortal)

Stack trace

20w51a: crash-2021-01-05_19.11.54-server.txt

Description: Exception while ticking

java.lang.IllegalStateException: Unable to get CCW facing of down
	at gc.h(SourceFile:305)
	at bwc.b(SourceFile:184)
	at bwc.a(SourceFile:169)
	at gy$10.a(SourceFile:428)
	at gx.dispense(SourceFile:15)
	at byg.a(SourceFile:90)
	at byg.a(SourceFile:113)
	at cgz$a.a(SourceFile:883)
	at aas.b(SourceFile:676)
	at aas$$Lambda$4739/325593810.accept(Unknown Source)
	at buf.b(SourceFile:84)
	at aas.a(SourceFile:367)
	at net.minecraft.server.MinecraftServer.b(SourceFile:870)
	at net.minecraft.server.MinecraftServer.a(SourceFile:810)
	at etq.a(SourceFile:93)
	at net.minecraft.server.MinecraftServer.w(SourceFile:669)
	at net.minecraft.server.MinecraftServer.a(SourceFile:257)
	at net.minecraft.server.MinecraftServer$$Lambda$4728/1911450914.run(Unknown Source)
	at java.lang.Thread.run(Thread.java:745)