Align flags with make

This pulls a number of cflag changes from make since our last sync.

Change-Id: I8c77fc215ed7677b8ac15a6d39143b519068dd55
diff --git a/cc/x86_linux_host.go b/cc/x86_linux_host.go
index 3bf9671..d1a92f1 100644
--- a/cc/x86_linux_host.go
+++ b/cc/x86_linux_host.go
@@ -69,6 +69,7 @@
 	linuxClangCflags = append([]string{
 		"--gcc-toolchain=${linuxGccRoot}",
 		"--sysroot=${linuxGccRoot}/sysroot",
+		"-fstack-protector-strong",
 	}, clangFilterUnknownCflags(linuxCflags)...)
 
 	linuxClangLdflags = append([]string{