[build] Create the link for the final library install name in the lib dir.

- Otherwise, we never were actually linking against the right library when
   building the test applications.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@174470 91177308-0d34-0410-b5e6-96231b3b80d8

lib/buildit

@@ -119,6 +119,21 @@ $CC *.o $RC_CFLAGS $LDSHARED_FLAGS $EXTRA_FLAGS
 
 #libtool -static -o libc++.a *.o
 
+# Create the link for the final library name, so that we can use this directory
+# as a link target for the tests.
+case $TRIPLE in
+    *-apple-*)
+        rm -f libc++.dylib
+        ln -s libc++.1.dylib libc++.dylib
+        ;;
+    *-*-mingw*)
+        ;;
+    *)
+        rm -f libc++.so
+        ln -s libc++.so.1 libc++.so
+        ;;
+esac
+
 if [ -z $RC_XBS ]
 then
     rm *.o