Maintain logging ABI compatiblity with YosysHQ Verific Extensions

The YosysHQ Verific Extensions are compiled separately using their own
stripped-down version of the Yosys headers. To maintain ABI
compatibility with older extension builds post C++-ification of Yosys's
logging APIs, which are backwards compatible on the API but not ABI
level, this commit adds ABI compatible versions of a subset of the old
logging API used by the extensions.

Makefile

@@ -633,6 +633,9 @@ $(eval $(call add_include_file,backends/rtlil/rtlil_backend.h))
 
 OBJS += kernel/driver.o kernel/register.o kernel/rtlil.o kernel/log.o kernel/calc.o kernel/yosys.o kernel/io.o kernel/gzip.o
 OBJS += kernel/log_help.o
+ifeq ($(ENABLE_VERIFIC_YOSYSHQ_EXTENSIONS),1)
+OBJS += kernel/log_compat.o
+endif
 OBJS += kernel/binding.o kernel/tclapi.o
 OBJS += kernel/cellaigs.o kernel/celledges.o kernel/cost.o kernel/satgen.o kernel/scopeinfo.o kernel/qcsat.o kernel/mem.o kernel/ffmerge.o kernel/ff.o kernel/yw.o kernel/json.o kernel/fmt.o kernel/sexpr.o
 OBJS += kernel/drivertools.o kernel/functional.o