[m-rev.] diff: Delete old code setting GC_stackbottom on AIX.

[Peter Wang]

util/mkinit.c:
    Delete last reference to GC_stackbottom (which has been deprecated).
    The code to set GC_stackbottom was only left for old AIX, but is not
    required at least with AIX 7.1 on POWER, and likely hasn't been
    relevant for a long time.

diff --git a/util/mkinit.c b/util/mkinit.c
index f807db677..b3e0715f9 100644
--- a/util/mkinit.c
+++ b/util/mkinit.c
@@ -384,24 +384,16 @@ static const char mercury_funcs1[] =
     "#if defined(MR_CONSERVATIVE_GC)\n"
     "   /*\n"
     "   ** Explicitly register the bottom of the stack, so that the\n"
-    "   ** GC knows where it starts.  This is necessary for AIX 4.1\n"
-    "   ** on RS/6000, and for gnu-win32 on Windows 95 or NT.\n"
-    "   ** It may also be helpful on other systems.\n"
-    "   ** For the Boehm GC, if the stackbottom argument is NULL then\n"
-    "   ** do not explicitly register the bottom of the stack, but\n"
-    "   ** let the collector determine an appropriate value itself.\n"
+    "   ** GC knows where it starts.\n"
     "   **\n"
     "   ** Boehm GC 7.4.2 deprecates the use of GC_stackbottom and\n"
     "   ** prohibits the use of the alternative GC_register_my_thread()\n"
     "   ** for the primordial thread. Therefore we do not attempt to\n"
-    "   ** register the bottom of the C stack except on AIX.\n"
+    "   ** register the bottom of the C stack but let the collector\n"
+    "   ** determine an appropriate value itself.\n"
     "   */\n"
     "   #if defined(MR_HGC)\n"
     "    MR_hgc_set_stack_bot(stackbottom);\n"
-    "   #elif defined(MR_BOEHM_GC) && defined(_AIX)\n"
-    "       if (stackbottom != NULL) {\n"
-    "           GC_stackbottom = stackbottom;\n"
-    "       }\n"
     "   #endif\n"
     "#endif\n"
     "\n"
-- 
2.21.0