11646 fbt entry probes incorrectly placed due to -fshrink-wrap

*** 23,33 ****
  # Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
  # Copyright (c) 2011 Bayard G. Bell. All rights reserved.
  # Copyright (c) 2011,2017 by Delphix. All rights reserved.
  # Copyright (c) 2013 Andrew Stormont.  All rights reserved.
  # Copyright 2016 Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
! # Copyright (c) 2019, Joyent, Inc.
  #
  
  #
  #       This Makefile contains the common targets and definitions for
  #       all kernels. It is to be included in the Makefiles for specific
--- 23,33 ----
  # Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
  # Copyright (c) 2011 Bayard G. Bell. All rights reserved.
  # Copyright (c) 2011,2017 by Delphix. All rights reserved.
  # Copyright (c) 2013 Andrew Stormont.  All rights reserved.
  # Copyright 2016 Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
! # Copyright 2019 Joyent, Inc.
  #
  
  #
  #       This Makefile contains the common targets and definitions for
  #       all kernels. It is to be included in the Makefiles for specific
*** 239,248 ****
--- 239,256 ----
  # Unfortunately, _IOWR() is regularly used with a third argument of 0,
  # so we have to disable all these smatch checks.
  #
  SMOFF += sizeof
  
+ #
+ # Ensure that the standard function prologue remains at the very start of a function,
+ # so DTrace fbt will instrument the right place.
+ #
+ CFLAGS_uts_i386 += -_gcc7=-fno-shrink-wrap
+ CFLAGS_uts_i386 += -_gcc8=-fno-shrink-wrap
+ CFLAGS_uts_i386 += -_gcc9=-fno-shrink-wrap
+ 
  CSTD = $(CSTD_GNU99)
  
  CFLAGS_uts              =
  CFLAGS_uts              += $(STAND_FLAGS_$(CLASS))
  CFLAGS_uts              += $(CCVERBOSE)
*** 255,264 ****
--- 263,273 ----
  CFLAGS_uts              += $(CCNOAGGRESSIVELOOPS)
  CFLAGS_uts              += $(CGLOBALSTATIC)
  CFLAGS_uts              += $(EXTRA_CFLAGS)
  CFLAGS_uts              += $(CSOURCEDEBUGFLAGS)
  CFLAGS_uts              += $(CUSERFLAGS)
+ CFLAGS_uts              += $(CFLAGS_uts_$(MACH))
  
  #
  #       Declare that $(OBJECTS) and $(LINTS) can be compiled in parallel.
  #       The DUMMY target is for those instances where OBJECTS and LINTS
  #       are empty (to avoid an unconditional .PARALLEL).