Use -nostdlib++ instead of -nodefaultlibs

Host builds using libc++ used -nodefaultlibs to turn off the default
C++ runtime, and then added back all the other necessary libraries.
Clang supports -nostdlib++ since https://reviews.llvm.org/D47115
that removes the C++ runtime without affecting the other default
libraries.  Use -nostdlib++, and remove the lists of default
libraries.

Test: m checkbuild
Change-Id: Ib8b761534f64fd7f881e14598e514783678e0b35
diff --git a/core/cxx_stl_setup.mk b/core/cxx_stl_setup.mk
index 8e4a46c..95b1090 100644
--- a/core/cxx_stl_setup.mk
+++ b/core/cxx_stl_setup.mk
@@ -33,12 +33,6 @@
     endif
 endif
 
-# Yes, this is actually what the clang driver does.
-linux_dynamic_gcclibs := -lgcc_s -lgcc -lc -lgcc_s -lgcc
-linux_static_gcclibs := -Wl,--start-group -lgcc -lgcc_eh -lc -Wl,--end-group
-darwin_dynamic_gcclibs := -lc -lSystem
-darwin_static_gcclibs := NO_STATIC_HOST_BINARIES_ON_DARWIN
-
 my_link_type := dynamic
 ifdef LOCAL_IS_HOST_MODULE
     ifneq (,$(BUILD_HOST_static))
@@ -79,8 +73,7 @@
 
     ifdef LOCAL_IS_HOST_MODULE
         my_cppflags += -nostdinc++
-        my_ldflags += -nodefaultlibs
-        my_cxx_ldlibs += $($($(my_prefix)OS)_$(my_link_type)_gcclibs)
+        my_ldflags += -nostdlib++
     else
         my_static_libraries += libc++demangle
         ifeq (arm,$($(my_prefix)$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH))
@@ -99,8 +92,7 @@
 else ifeq ($(my_cxx_stl),none)
     ifdef LOCAL_IS_HOST_MODULE
         my_cppflags += -nostdinc++
-        my_ldflags += -nodefaultlibs
-        my_cxx_ldlibs += $($($(my_prefix)OS)_$(my_link_type)_gcclibs)
+        my_ldflags += -nostdlib++
     endif
 else
     $(error $(LOCAL_PATH): $(LOCAL_MODULE): $(my_cxx_stl) is not a supported STL.)