More test notes from using build.sh against non NetBSD platforms.

tools/compat/README

@@ -1,4 +1,4 @@
-$NetBSD: README,v 1.14 2021/05/06 07:32:15 cjep Exp $
+$NetBSD: README,v 1.15 2021/05/07 14:52:59 cjep Exp $
 
 Special notes for cross-hosting a NetBSD build on certain platforms.  
 Only those platforms which have been tested to complete a "build.sh" run
@@ -16,17 +16,22 @@ In addition all hosts must provide the following local tools:
 FreeBSD
 =======
 
-build.sh was recently tested on FreeBSD 13 with the compiler tools installed.
+build.sh was recently tested on:
+* FreeBSD 13 (amd64, aarch64) 
+* FreeBSD 12.2 (amd64, aarch64)
+* FreeBSD 11.4 (amd64)
+* FreeBSD 10.4 (amd64)
 
 Linux
 =====
 
 build.sh has been tested on:
 * Amazon Linux 2 (x86)
-* Debian 10 (x86)
-* Red Hat Enterprise Linux 8 (x86)
+* Debian 10 (x86, aarch64)
+* Red Hat Enterprise Linux 8 (x86, aarch64)
 * SUSE Enterprise Server 15 (x86)
-* Ubuntu Server 20.04 (x86)
+* Ubuntu Server 20.04 (x86, aarch64)
+* Ubuntu Server 18.04 (x86)
 
 * The gcc and g++ package must be installed, along with the typical system 
   development packages (glibc-devel, etc.). The g++ package is sometimes 
@@ -37,12 +42,18 @@ build.sh has been tested on:
 * The zlib and zlib-devel packages must be installed (these are
   called zlib1g and zlib1g-dev on Debian and Ubuntu Linux)
 
+* There is a known build problem on Linux/aarch64 with glibc <2.28
+
 macOS/Darwin
 ============
 
-build.sh was recently tested on macOS Big Sur with an APFS filesystem
-and the Xcode command line tools. (Previously, there have been issues
-building on case-insensitive HFS filesystems.)
+build.sh was recently tested on:
+* macOS Big Sur
+* macOS Catalina
+
+with up to date Xcode command line tools and APFS filesystems.
+(Previously, there have been issues building on case-insensitive 
+HFS filesystems.)
 
 HP-UX
 =====