Mark __BIONIC_WEAK_FOR_NATIVE_BRIDGE symbols

To make it easier for Native Bridge implementations
to override these symbols.

Bug: http://b/67993967
Test: make
Change-Id: I4c53e53af494bca365dd2b3305ab0ccc2b23ba44
diff --git a/libc/arch-x86/bionic/setjmp.S b/libc/arch-x86/bionic/setjmp.S
index efb6459..6e6c365 100644
--- a/libc/arch-x86/bionic/setjmp.S
+++ b/libc/arch-x86/bionic/setjmp.S
@@ -78,18 +78,21 @@
 .endm
 
 ENTRY(setjmp)
+__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(setjmp)
   movl 4(%esp),%ecx
   mov $1,%eax
   jmp .L_sigsetjmp
 END(setjmp)
 
 ENTRY(_setjmp)
+__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(_setjmp)
   movl 4(%esp),%ecx
   movl $0,%eax
   jmp .L_sigsetjmp
 END(_setjmp)
 
 ENTRY(sigsetjmp)
+__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(sigsetjmp)
   movl 4(%esp),%ecx
   movl 8(%esp),%eax
 
@@ -142,6 +145,7 @@
 END(sigsetjmp)
 
 ENTRY(siglongjmp)
+__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(siglongjmp)
   movl 4(%esp),%edx
 
   // Check the checksum before doing anything.
@@ -205,4 +209,6 @@
 END(siglongjmp)
 
 ALIAS_SYMBOL(longjmp, siglongjmp)
+__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(longjmp)
 ALIAS_SYMBOL(_longjmp, siglongjmp)
+__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(_longjmp)
diff --git a/libc/arch-x86/bionic/vfork.S b/libc/arch-x86/bionic/vfork.S
index 5c71b8d..79d7899 100644
--- a/libc/arch-x86/bionic/vfork.S
+++ b/libc/arch-x86/bionic/vfork.S
@@ -31,6 +31,7 @@
 // This custom code preserves the return address across the system call.
 
 ENTRY(vfork)
+__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(vfork)
   popl    %ecx  // Grab the return address.
   .cfi_adjust_cfa_offset 4
   .cfi_rel_offset ecx, 0