Remove build/libs

There's only a single library, libhost, and it's only used by acp and
atree in build/tools, move it there.

Bug: 28001743
Change-Id: Ie404d2793710de4e265a6fa95d462c32d4042623

tools/libhost/include/host/CopyFile.h

@@ -0,0 +1,30 @@
+#ifndef _HOST_COPYFILE_H
+#define _HOST_COPYFILE_H
+
+#include <stdbool.h>
+#include <sys/stat.h>
+
+#if __cplusplus
+extern "C" {
+#endif
+
+// command line options
+enum {
+    COPY_NO_DEREFERENCE = 0x00010000, // copy symlink link instead of target
+    COPY_TRY_EXE        = 0x00020000, // on Win32, try adding '.exe' to filename
+    COPY_FORCE          = 0x00040000, // override access permissions
+    COPY_PERMISSIONS    = 0x00080000, // preserve mode, ownership, timestamps
+    COPY_TIMESTAMPS     = 0x00100000, // preserve mode, ownership, timestamps
+    COPY_RECURSIVE      = 0x00200000, // copy directories
+    COPY_UPDATE_ONLY    = 0x00400000, // only copy if source file is newer
+    COPY_VERBOSE_MASK   = 0x000000ff  // talk lots
+};
+
+int copyFile(const char* src, const char* dst, unsigned int options);
+
+#if __cplusplus
+} // extern "C"
+#endif
+
+#endif // _HOST_COPYFILE_H
+