Use the asm version by default on x86. Tag _start as a function.

libc/sysdeps/linux/i386/Makefile

@@ -20,7 +20,7 @@
 # other sundry sources.  Files within this library are copyright by their
 # respective copyright holders.
 
-USE_CRT0_C=true
+USE_CRT0_C=false
 
 TOPDIR=../../../../
 include $(TOPDIR)Rules.mak

libc/sysdeps/linux/i386/crt0.S

@@ -30,9 +30,12 @@ Cambridge, MA 02139, USA.  */
         NULL
 */
 
-.global _start
-
 .text
+	.align 4
+
+.globl _start
+	.type	 _start,@function
+
 _start:
 	/* First locate the start of the environment variables */
 	popl %ecx	/* Store argc into %ecx */