android/build.py: drop --sysroot, -isystem, -L, ...

These appear to be no longer necessary (tested with NDK r20b).

Closes android/ndk#951

android/build.py

@@ -75,20 +75,14 @@ def __init__(self, tarball_path, src_path, build_path,
 
         ndk_arch = abi_info['ndk_arch']
         android_api_level = '21'
-        ndk_platform = 'android-' + android_api_level
 
         # select the NDK compiler
         gcc_version = '4.9'
 
-        ndk_platform_path = os.path.join(ndk_path, 'platforms', ndk_platform)
-        sysroot = os.path.join(ndk_path, 'sysroot')
-        target_root = os.path.join(ndk_platform_path, 'arch-' + ndk_arch)
-
         install_prefix = os.path.join(arch_path, 'root')
 
         self.arch = arch
         self.install_prefix = install_prefix
-        self.sysroot = sysroot
 
         toolchain_path = os.path.join(ndk_path, 'toolchains', abi_info['toolchain_arch'] + '-' + gcc_version, 'prebuilt', build_arch)
         llvm_path = os.path.join(ndk_path, 'toolchains', 'llvm', 'prebuilt', build_arch)
@@ -113,28 +107,21 @@ def __init__(self, tarball_path, src_path, build_path,
 
         self.cflags = common_flags
         self.cxxflags = common_flags
-        self.cppflags = '--sysroot=' + sysroot + \
-            ' -isystem ' + os.path.join(install_prefix, 'include') + \
-            ' -isystem ' + os.path.join(sysroot, 'usr', 'include', arch)
-        self.ldflags = '--sysroot=' + sysroot + \
-            ' -L' + os.path.join(install_prefix, 'lib') + \
-            ' -L' + os.path.join(target_root, 'usr', 'lib') + \
-            ' -B' + os.path.join(target_root, 'usr', 'lib') + \
+        self.cppflags = ' -isystem ' + os.path.join(install_prefix, 'include')
+        self.ldflags = ' -L' + os.path.join(install_prefix, 'lib') + \
             ' ' + common_flags
+        self.ldflags = common_flags
         self.libs = ''
 
         self.is_arm = ndk_arch == 'arm'
         self.is_armv7 = self.is_arm and 'armv7' in self.cflags
         self.is_aarch64 = ndk_arch == 'arm64'
         self.is_windows = False
 
-        libcxx_path = os.path.join(ndk_path, 'sources/cxx-stl/llvm-libc++')
-        libcxx_libs_path = os.path.join(libcxx_path, 'libs', android_abi)
-
         libstdcxx_flags = ''
-        libstdcxx_cxxflags = libstdcxx_flags + ' -isystem ' + os.path.join(libcxx_path, 'include') + ' -isystem ' + os.path.join(ndk_path, 'sources/android/support/include')
-        libstdcxx_ldflags = libstdcxx_flags + ' -L' + libcxx_libs_path
-        libstdcxx_libs = '-lc++_static -lc++abi'
+        libstdcxx_cxxflags = ''
+        libstdcxx_ldflags = ''
+        libstdcxx_libs = '-static-libstdc++'
 
         if self.is_armv7:
             # On 32 bit ARM, clang generates no ".eh_frame" section;