meson: Deprecate 32-bit host support

We deprecated i686 system mode support for qemu 8.0.  However, to
make real cleanups to TCG we need to deprecate all 32-bit hosts.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

docs/about/deprecated.rst

@@ -204,6 +204,13 @@ is going to be so much slower it wouldn't make sense for any serious
 instrumentation. Due to implementation differences there will also be
 anomalies in things like memory instrumentation.
 
+32-bit host operating systems (since 10.0)
+''''''''''''''''''''''''''''''''''''''''''
+
+Keeping 32-bit host support alive is a substantial burden for the
+QEMU project.  Thus QEMU will in future drop the support for all
+32-bit host systems.
+
 System emulator CPUs
 --------------------
 

meson.build

@@ -4841,14 +4841,12 @@ if host_arch == 'unknown'
     message('configure has succeeded and you can continue to build, but')
     message('QEMU will use a slow interpreter to emulate the target CPU.')
   endif
-elif host_arch == 'mips'
+elif host_long_bits < 64
   message()
   warning('DEPRECATED HOST CPU')
   message()
-  message('Support for CPU host architecture ' + cpu + ' is going to be')
-  message('dropped as soon as the QEMU project stops supporting Debian 12')
-  message('("Bookworm"). Going forward, the QEMU project will not guarantee')
-  message('that QEMU will compile or work on this host CPU.')
+  message('Support for 32-bit CPU host architecture ' + cpu + ' is going')
+  message('to be dropped in a future QEMU release.')
 endif
 
 if not supported_oses.contains(host_os)