[CMake][Fuchsia] Enable hermetic static libunwind for Fuchsia

In addition to libc++abi and libc++, we also want to use hermetic
static libunwind on Fuchsia.

Differential Revision: https://reviews.llvm.org/D57431

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@352584 91177308-0d34-0410-b5e6-96231b3b80d8

cmake/caches/Fuchsia-stage2.cmake

@@ -114,6 +114,7 @@ if(FUCHSIA_SDK)
     set(RUNTIMES_${target}-fuchsia_CMAKE_SYSROOT ${FUCHSIA_${target}_SYSROOT} CACHE PATH "")
     set(RUNTIMES_${target}-fuchsia_LLVM_ENABLE_ASSERTIONS ON CACHE BOOL "")
     set(RUNTIMES_${target}-fuchsia_LIBUNWIND_USE_COMPILER_RT ON CACHE BOOL "")
+    set(RUNTIMES_${target}-fuchsia_LIBUNWIND_HERMETIC_STATIC_LIBRARY ON CACHE BOOL "")
     set(RUNTIMES_${target}-fuchsia_LIBUNWIND_INSTALL_STATIC_LIBRARY OFF CACHE BOOL "")
     set(RUNTIMES_${target}-fuchsia_LIBCXXABI_USE_COMPILER_RT ON CACHE BOOL "")
     set(RUNTIMES_${target}-fuchsia_LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")