9939 Need to stop GCC reordering functions

@@ -339,16 +339,24 @@
 # emitted instead of function names
 CCNOAUTOINLINE= \
         -_gcc=-fno-inline-small-functions \
         -_gcc=-fno-inline-functions-called-once \
         -_gcc=-fno-ipa-cp \
-        -_gcc6=-fno-ipa-icf \
         -_gcc7=-fno-ipa-icf \
         -_gcc8=-fno-ipa-icf \
-        -_gcc6=-fno-clone-functions \
         -_gcc7=-fno-clone-functions \
-        -_gcc8=-fno-clone-functions
+        -_gcc8=-fno-clone-functions \
+
+# GCC may put functions in different named sub-sections of .text based on
+# their presumed calling frequency.  At least in the kernel, where we actually
+# deliver relocatable objects, we don't want this to happen.
+#
+# Since at present we don't benefit from this even in userland, we disable it globally,
+# but the application of this may move into usr/src/uts/ in future.
+CCNOREORDER=    \
+        -_gcc7=-fno-reorder-functions \
+        -_gcc8=-fno-reorder-functions
 
 # One optimization the compiler might perform is to turn this:
 #       #pragma weak foo
 #       extern int foo;
 #       if (&foo)

@@ -564,24 +572,24 @@
 $(SRCDBGBLD)CSOURCEDEBUGFLAGS   = -g -xs
 $(SRCDBGBLD)CCSOURCEDEBUGFLAGS  = -g -xs
 
 CFLAGS=         $(COPTFLAG) $($(MACH)_CFLAGS) $(SPACEFLAG) $(CCMODE) \
                 $(ILDOFF) $(CERRWARN) $(CSTD) $(CCUNBOUND) $(IROPTFLAG) \
-                $(CGLOBALSTATIC) $(CCNOAUTOINLINE) $(CSOURCEDEBUGFLAGS) \
-                $(CUSERFLAGS)
+                $(CGLOBALSTATIC) $(CCNOAUTOINLINE) $(CCNOREORDER) \
+                $(CSOURCEDEBUGFLAGS) $(CUSERFLAGS)
 CFLAGS64=       $(COPTFLAG64) $($(MACH64)_CFLAGS) $(SPACEFLAG64) $(CCMODE64) \
                 $(ILDOFF) $(CERRWARN) $(CSTD) $(CCUNBOUND) $(IROPTFLAG64) \
-                $(CGLOBALSTATIC) $(CCNOAUTOINLINE) $(CSOURCEDEBUGFLAGS) \
-                $(CUSERFLAGS64)
+                $(CGLOBALSTATIC) $(CCNOAUTOINLINE) $(CCNOREORDER) \
+                $(CSOURCEDEBUGFLAGS) $(CUSERFLAGS64)
 #
 # Flags that are used to build parts of the code that are subsequently
 # run on the build machine (also known as the NATIVE_BUILD).
 #
 NATIVE_CFLAGS=  $(COPTFLAG) $($(NATIVE_MACH)_CFLAGS) $(CCMODE) \
                 $(ILDOFF) $(CERRWARN) $(CSTD) $($(NATIVE_MACH)_CCUNBOUND) \
                 $(IROPTFLAG) $(CGLOBALSTATIC) $(CCNOAUTOINLINE) \
-                $(CSOURCEDEBUGFLAGS) $(CUSERFLAGS)
+                $(CCNOREORDER) $(CSOURCEDEBUGFLAGS) $(CUSERFLAGS)
 
 DTEXTDOM=-DTEXT_DOMAIN=\"$(TEXT_DOMAIN)\"       # For messaging.
 DTS_ERRNO=-D_TS_ERRNO
 CPPFLAGS.first= # Please keep empty.  Only lower makefiles should set this.
 CPPFLAGS.master=$(DTEXTDOM) $(DTS_ERRNO) \