message: Remove useless ARCHS declarations in the Xcode project.
diff: buildSettings = {
  ALWAYS_SEARCH_USER_PATHS = NO;
  ARCHS = "$(ARCHS_STANDARD_64_BIT)";
  - "ARCHS[sdk=iphoneos*]" = (
  - arm64,
  - armv7,
  - );
  - "ARCHS[sdk=macosx*]" = (
  - x86_64,
  - i386,
  - );
  CLANG_ANALYZER_OTHER_FLAGS = "-analyzer-config suppress-null-return-paths=false";
  CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
  CLANG_CXX_LIBRARY = "libc++";
  buildSettings = {
  ALWAYS_SEARCH_USER_PATHS = NO;
  ARCHS = "$(ARCHS_STANDARD_64_BIT)";
  - "ARCHS[sdk=iphoneos*]" = (
  - armv7,
  - arm64,
  - );
  - "ARCHS[sdk=macosx*]" = (
  - x86_64,
  - i386,
  - );
  CLANG_ANALYZER_OTHER_FLAGS = "-analyzer-config suppress-null-return-paths=false";
  CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
  CLANG_CXX_LIBRARY = "libc++";
  buildSettings = {
  ALWAYS_SEARCH_USER_PATHS = NO;
  ARCHS = "$(ARCHS_STANDARD_64_BIT)";
  - "ARCHS[sdk=iphoneos*]" = (
  - armv7,
  - arm64,
  - );
  - "ARCHS[sdk=macosx*]" = (
  - x86_64,
  - i386,
  - );
  CLANG_ANALYZER_OTHER_FLAGS = "-analyzer-config suppress-null-return-paths=false";
  CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
  CLANG_CXX_LIBRARY = "libc++";
  buildSettings = {
  ALWAYS_SEARCH_USER_PATHS = NO;
  ARCHS = "$(ARCHS_STANDARD_64_BIT)";
  - "ARCHS[sdk=iphoneos*]" = (
  - armv7,
  - arm64,
  - );
  - "ARCHS[sdk=macosx*]" = (
  - x86_64,
  - i386,
  - );
  CLANG_ANALYZER_OTHER_FLAGS = "-analyzer-config suppress-null-return-paths=false";
  CLANG_CXX_LANGUAGE_STANDARD = "c++0x";
  CLANG_CXX_LIBRARY = "libc++";
  