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_64/bionic/setjmp.S b/libc/arch-x86_64/bionic/setjmp.S
index 34b4365..1d34561 100644
--- a/libc/arch-x86_64/bionic/setjmp.S
+++ b/libc/arch-x86_64/bionic/setjmp.S
@@ -91,17 +91,20 @@
 .endm
 
 ENTRY(setjmp)
+__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(setjmp)
   movl $1,%esi
   jmp PIC_PLT(sigsetjmp)
 END(setjmp)
 
 ENTRY(_setjmp)
+__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(_setjmp)
   movl $0,%esi
   jmp PIC_PLT(sigsetjmp)
 END(_setjmp)
 
 // int sigsetjmp(sigjmp_buf env, int save_signal_mask);
 ENTRY(sigsetjmp)
+__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(sigsetjmp)
   pushq %rdi
   movq %rsi,%rdi
   call PIC_PLT(__bionic_setjmp_cookie_get)
@@ -148,6 +151,7 @@
 
 // void siglongjmp(sigjmp_buf env, int value);
 ENTRY(siglongjmp)
+__BIONIC_WEAK_ASM_FOR_NATIVE_BRIDGE(siglongjmp)
   movq %rdi,%r12
   pushq %rsi // Push 'value'.
 
@@ -206,4 +210,6 @@
 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_64/bionic/vfork.S b/libc/arch-x86_64/bionic/vfork.S
index 3b32c66..ce96a8c 100644
--- a/libc/arch-x86_64/bionic/vfork.S
+++ b/libc/arch-x86_64/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)
   popq    %rdi  // Grab the return address.
 
   // __get_tls()[TLS_SLOT_THREAD_ID]->cached_pid_ = 0