[MIPS64] Make __clear_cache more optimal
[MIPS64] Make __clear_cache more optimal

Use synci implementation of clear_cache for short address ranges.
For long address ranges, make a kernel call.

Differential Revision: http://reviews.llvm.org/D6661


git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@226567 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