Pass --wrap=pthread_create to linker for -fsplit-stack.

From

https://gcc.gnu.org/ml/gcc-patches/2010-09/msg01807.html

-fsplit-stack should pass --wrap=pthread_create to linker for -fsplit-stack
It is needed to initialize the stack guard.  This fixes PR 20148.

Patch by H.J Lu!

llvm-svn: 258698
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 6a1517f..574bf5c 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -9001,6 +9001,9 @@
       if (WantPthread && !isAndroid)
         CmdArgs.push_back("-lpthread");
 
+      if (Args.hasArg(options::OPT_fsplit_stack))
+        CmdArgs.push_back("--wrap=pthread_create");
+
       CmdArgs.push_back("-lc");
 
       if (Args.hasArg(options::OPT_static))