SERVER-24117 Force the stack to always be non-executable

Also, warn if the stack would have been executable if we hadn't forced
it not to be, so we can find and correct broken assmbley source files.

(cherry picked from commit 23c5d7e)

SConstruct

@@ -2122,6 +2122,17 @@ def doConfigure(myenv):
     if myenv.ToolchainIs('gcc', 'clang'):
         AddToLINKFLAGSIfSupported(myenv, '-fuse-ld=gold')
 
+        # Disallow an executable stack. Also, issue a warning if any files are found that would
+        # cause the stack to become executable if the noexecstack flag was not in play, so that we
+        # can find them and fix them. We do this here after we check for ld.gold because the
+        # --warn-execstack is currently only offered with gold.
+        #
+        # TODO: Add -Wl,--fatal-warnings once WT-2629 is fixed. We probably can do that
+        # unconditionally above, and not need to do it as an AddToLINKFLAGSIfSupported step, since
+        # both gold and binutils ld both support it.
+        AddToLINKFLAGSIfSupported(myenv, "-Wl,-z,noexecstack")
+        AddToLINKFLAGSIfSupported(myenv, "-Wl,--warn-execstack")
+
     # Apply any link time optimization settings as selected by the 'lto' option.
     if has_option('lto'):
         if myenv.ToolchainIs('msvc'):