11462 enable smatch by default

*** 6,16 ****
  #
  # A full copy of the text of the CDDL should have accompanied this
  # source.  A copy of the CDDL is also available via the Internet at
  # http://www.illumos.org/license/CDDL.
  #
! # Copyright (c) 2019, Joyent, Inc.
  #
  
  #
  # smatch/sparse checks we always disable, due to too many false positives (or
  # simply too much legacy).
--- 6,16 ----
  #
  # A full copy of the text of the CDDL should have accompanied this
  # source.  A copy of the CDDL is also available via the Internet at
  # http://www.illumos.org/license/CDDL.
  #
! # Copyright 2019 Joyent, Inc.
  #
  
  #
  # smatch/sparse checks we always disable, due to too many false positives (or
  # simply too much legacy).
*** 25,34 ****
--- 25,36 ----
  # there are lots of "extern void myfunc() { ... }" around
  SMATCH_ARGS += -Wno-external-function-has-definition
  # we have lots of legacy "void foo();" in headers
  SMATCH_ARGS += -Wno-old-style-definition
  SMATCH_ARGS += -Wno-strict-prototypes
+ SMATCH_ARGS += --fatal-checks
+ SMATCH_ARGS += --timeout=120
  
  CERRWARN += $(SMATCH_ARGS:%=-_smatch=%)
  
  CERRWARN += $(SMOFF:%=-_smatch=--disable=%)