Temporary apply LIBC version to __pthread_gettid

This is workaround for http://b/26391427

Bug: http://b/26391427
Change-Id: Ibf5c611cf4c04dfa595644225e6d9503089a18da

libc/bionic/ndk_cruft.cpp

@@ -340,10 +340,17 @@ size_t dlmalloc_usable_size(void* ptr) {
 }
 
 // In L we added a public pthread_gettid_np, but some apps were using the private API.
-pid_t __pthread_gettid(pthread_t t) {
+pid_t __pthread_gettid_libc(pthread_t t) {
   return pthread_gettid_np(t);
 }
 
+pid_t __pthread_gettid_libc_private(pthread_t t) {
+  return pthread_gettid_np(t);
+}
+
+__asm__(".symver __pthread_gettid_libc,__pthread_gettid@LIBC");
+__asm__(".symver __pthread_gettid_libc_private,__pthread_gettid@@LIBC_PRIVATE");
+
 // Older versions of apportable used dlmalloc directly instead of malloc,
 // so export this compatibility shim that simply calls malloc.
 void* dlmalloc(size_t size) {

libc/libc.arm.map

@@ -122,6 +122,7 @@ LIBC {
     __pselect6; # arm x86 mips
     __pthread_cleanup_pop;
     __pthread_cleanup_push;
+    __pthread_gettid; # arm x86 mips nobrillo
     __ptrace; # arm x86 mips
     __putlong;
     __putshort;

libc/libc.map.txt

@@ -123,6 +123,7 @@ LIBC {
     __pselect6; # arm x86 mips
     __pthread_cleanup_pop;
     __pthread_cleanup_push;
+    __pthread_gettid; # arm x86 mips nobrillo
     __ptrace; # arm x86 mips
     __putlong;
     __putshort;

libc/libc.mips.map

@@ -120,6 +120,7 @@ LIBC {
     __pselect6; # arm x86 mips
     __pthread_cleanup_pop;
     __pthread_cleanup_push;
+    __pthread_gettid; # arm x86 mips nobrillo
     __ptrace; # arm x86 mips
     __putlong;
     __putshort;

libc/libc.x86.map

@@ -120,6 +120,7 @@ LIBC {
     __pselect6; # arm x86 mips
     __pthread_cleanup_pop;
     __pthread_cleanup_push;
+    __pthread_gettid; # arm x86 mips nobrillo
     __ptrace; # arm x86 mips
     __putlong;
     __putshort;