8c4994bbc1
The old __isthreaded hack was never very useful on Android because all user code runs in a VM where there are lots of threads running. But __fsetlocking lets a caller say "I'll worry about the locking for this FILE*", which is useful for the normal case where you don't share a FILE* between threads so you don't need any locking. Bug: 17154740 Bug: 18593728 Change-Id: I2a8dddc29d3edff39a3d7d793387f2253608a68d