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/silvermont/string/sse2-memset-slm.S b/libc/arch-x86/silvermont/string/sse2-memset-slm.S
index 03a552d..adaccae 100644
--- a/libc/arch-x86/silvermont/string/sse2-memset-slm.S
+++ b/libc/arch-x86/silvermont/string/sse2-memset-slm.S
@@ -86,7 +86,7 @@
 	movl	(%esp), %ebx
 	ret
 
-ENTRY(__memset_chk)
+ENTRY(__memset_chk_generic)
   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_generic)
 
 	.section .text.sse2,"ax",@progbits
 	ALIGN(4)
-ENTRY(memset)
+ENTRY(memset_generic)
 	ENTRANCE
 
 	movl	LEN(%esp), %ecx
@@ -758,4 +758,4 @@
 	SETRTNVAL
 	RETURN_END
 
-END(memset)
+END(memset_generic)