x86: fix full_x86-eng build

The latest merge conflict resolution worked only for ARM, but not for x86
Both ARM and x86 builds have been tested with this fix.

Change-Id: I4ec1f1b0ea32fa86e7e2515b221133473d6550a3
NOTE: Care has been taken to not change the compiler flags for ARM builds.
      In particular, when building crtbegin_so.so, the -fPIC flag is only
      used for x86 (previous reports indicate that it breaks the ARM
      build at runtime for obscure reasons).
diff --git a/libc/arch-x86/bionic/crtend_so.S b/libc/arch-x86/bionic/crtend_so.S
index 8c9d419..63e58b9 100644
--- a/libc/arch-x86/bionic/crtend_so.S
+++ b/libc/arch-x86/bionic/crtend_so.S
@@ -1,6 +1,12 @@
-
 .section .init_array, "aw"
     .long 0
 
 .section .fini_array, "aw"
     .long 0
+
+	.section	.eh_frame,"a",@progbits
+	.align 4
+	.type	__FRAME_END__, @object
+	.size	__FRAME_END__, 4
+__FRAME_END__:
+	.zero	4