databases/db4 on macOS 10.0.1/arm

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

I'm trying to get my newly arrived ARM ("Apple Silicon") MacBook Air running.

I'm using 2020Q3 with the OSX_VERSION fix in platform/Darwin.mk (I hunted the 
error myself up to the 11.00000 == 11.00000 to find it was fixed in -current).

Now, databases/db4 fails during configure with
	/bin/sh: line 1: 39149 Segmentation fault: 11 [...]

If I cd to work/db-4.8.40/build_unix and run the command, which is
	/usr/bin/env [...] /bin/sh ../dist/configure [...]
myself, it works.

Unfortunately, if, after that, I touch work/.configure_done and try 
make build, that fails.

I don't see any recent related commits in -current.

Any hints?