android: do not add rpaths when linking

the dynamic linker doesn't understand them and spams warnings.

Author: zhuowei

cmake/modules/AddSwift.cmake

@@ -922,7 +922,7 @@ function(_add_swift_library_single target name)
     set_target_properties("${target}"
       PROPERTIES
       INSTALL_NAME_DIR "${install_name_dir}")
-  elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
+  elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux" AND NOT "${SWIFTLIB_SINGLE_SDK}" STREQUAL "ANDROID")
     set_target_properties("${target}"
       PROPERTIES
       INSTALL_RPATH "$ORIGIN:/usr/lib/swift/linux")

lib/Driver/ToolChains.cpp

@@ -1135,15 +1135,17 @@ toolchains::GenericUnix::constructInvocation(const LinkJobAction &job,
 
     Arguments.push_back("-lgcc");
     Arguments.push_back("-lc");
+  } else {
+    // rpaths are not supported on Android.
+
+    // FIXME: We probably shouldn't be adding an rpath here unless we know ahead
+    // of time the standard library won't be copied.
+    Arguments.push_back("-Xlinker");
+    Arguments.push_back("-rpath");
+    Arguments.push_back("-Xlinker");
+    Arguments.push_back(context.Args.MakeArgString(RuntimeLibPath));
   }
 
-  // FIXME: We probably shouldn't be adding an rpath here unless we know ahead
-  // of time the standard library won't be copied.
-  Arguments.push_back("-Xlinker");
-  Arguments.push_back("-rpath");
-  Arguments.push_back("-Xlinker");
-  Arguments.push_back(context.Args.MakeArgString(RuntimeLibPath));
-
   // Always add the stdlib
   Arguments.push_back("-lswiftCore");