[Fuzzer] When building for Fuchsia, add an explicit libc++ dependency
[Fuzzer] When building for Fuchsia, add an explicit libc++ dependency

libFuzzer dependes on C++ library, when building for Fuchsia, we
need to ensure that libFuzzer is only being built after libc++
has been built, so we add an explicity dependency on it.

Differential Revision: https://reviews.llvm.org/D44340

git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@327196 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