Invalidate instruction cache when setting memory to be executable.

lli's remote MCJIT code calls setExecutable just prior to running
code. In line with Darwin behaviour this seems to be the place to
invalidate any caches needed so that relocations can take effect
properly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182213 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/Unix/Memory.inc

@@ -268,6 +268,9 @@ bool Memory::setExecutable (MemoryBlock &M, std::string *ErrMsg) {
   kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)M.Address,
     (vm_size_t)M.Size, 0, VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
   return KERN_SUCCESS == kr;
+#elif defined(__arm__) || defined(__aarch64__)
+  Memory::InvalidateInstructionCache(M.Address, M.Size);
+  return true;
 #else
   return true;
 #endif