Use ifunc to dynamically dispatch libc routines for x86

Test: run bionic unit test in aosp_cf_x86_phone emulator
Change-Id: Ib0c0de37cd38d24bfce2dfbe35b8fd8edff004af
diff --git a/libc/arch-x86/atom/string/sse2-memset-atom.S b/libc/arch-x86/atom/string/sse2-memset-atom.S
index 4e211ca..016c49e 100644
--- a/libc/arch-x86/atom/string/sse2-memset-atom.S
+++ b/libc/arch-x86/atom/string/sse2-memset-atom.S
@@ -86,7 +86,7 @@
 	movl	(%esp), %ebx
 	ret
 
-ENTRY(__memset_chk)
+ENTRY(__memset_chk_atom)
   ENTRANCE
 
   movl LEN(%esp), %ecx
@@ -95,11 +95,11 @@
 
   POP(%ebx) // Undo ENTRANCE without returning.
   jmp __memset_chk_fail
-END(__memset_chk)
+END(__memset_chk_atom)
 
 	.section .text.sse2,"ax",@progbits
 	ALIGN(4)
-ENTRY(memset)
+ENTRY(memset_atom)
 	ENTRANCE
 
 	movl	LEN(%esp), %ecx
@@ -839,4 +839,4 @@
 	SETRTNVAL
 	RETURN_END
 
-END(memset)
+END(memset_atom)