Improve performance of file I/O.
Improve performance of file I/O.

The fread / fwrite calls were happening for each timer. However, that could be
pretty expensive for a large number of timers. Instead, read and write the
timers in one call.

This gives ~10% speedup in compilation time.


git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@179990 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt