src: add "icu::" prefix before ICU symbols

In ICU 61.x, icu4c will no longer put its declarations in the global namespace.
Everything will be in the "icu::" namespace (or icu_60:: in the linker).
Prepare for this.
https://ssl.icu-project.org/trac/ticket/13460

src/inspector_io.cc

@@ -74,11 +74,11 @@ std::string StringViewToUtf8(const StringView& view) {

  size_t result_length = view.length() * sizeof(*source);
  std::string result(result_length, '\0');
  UnicodeString utf16(unicodeSource, view.length());
  icu::UnicodeString utf16(unicodeSource, view.length());
  // ICU components for std::string compatibility are not enabled in build...
  bool done = false;
  while (!done) {
    CheckedArrayByteSink sink(&result[0], result_length);
    icu::CheckedArrayByteSink sink(&result[0], result_length);
    utf16.toUTF8(sink);
    result_length = sink.NumberOfBytesAppended();
    result.resize(result_length);
@@ -111,8 +111,9 @@ void ReleasePairOnAsyncClose(uv_handle_t* async) {
}  // namespace

std::unique_ptr<StringBuffer> Utf8ToStringView(const std::string& message) {
  UnicodeString utf16 =
      UnicodeString::fromUTF8(StringPiece(message.data(), message.length()));
  icu::UnicodeString utf16 =
    icu::UnicodeString::fromUTF8(icu::StringPiece(message.data(),
      message.length()));
  StringView view(reinterpret_cast<const uint16_t*>(utf16.getBuffer()),
                  utf16.length());
  return StringBuffer::create(view);

src/node_i18n.cc

@@ -523,7 +523,7 @@ const char* GetVersion(const char* type,
  } else if (!strcmp(type, TYPE_UNICODE)) {
    return U_UNICODE_VERSION;
  } else if (!strcmp(type, TYPE_TZ)) {
    return TimeZone::getTZDataVersion(*status);
    return icu::TimeZone::getTZDataVersion(*status);
  } else if (!strcmp(type, TYPE_CLDR)) {
    UVersionInfo versionArray;
    ulocdata_getCLDRVersion(versionArray, status);

tools/icu/iculslocs.cc

@@ -64,7 +64,7 @@ int VERBOSE = 0;
#define RES_INDEX "res_index"
#define INSTALLEDLOCALES "InstalledLocales"

CharString packageName;
icu::CharString packageName;
const char* locale = RES_INDEX;  // locale referring to our index

void usage() {
@@ -147,7 +147,7 @@ int localeExists(const char* loc, UBool* exists) {
  if (VERBOSE > 1) {
    printf("Trying to open %s:%s\n", packageName.data(), loc);
  }
  LocalUResourceBundlePointer aResource(
  icu::LocalUResourceBundlePointer aResource(
      ures_openDirect(packageName.data(), loc, &status));
  *exists = FALSE;
  if (U_SUCCESS(status)) {
@@ -189,11 +189,11 @@ void printIndent(FILE* bf, int indent) {
 * @return 0 for OK, 1 for err
 */
int dumpAllButInstalledLocales(int lev,
                               LocalUResourceBundlePointer* bund,
                               icu::LocalUResourceBundlePointer* bund,
                               FILE* bf,
                               UErrorCode* status) {
  ures_resetIterator(bund->getAlias());
  LocalUResourceBundlePointer t;
  icu::LocalUResourceBundlePointer t;
  while (U_SUCCESS(*status) && ures_hasNext(bund->getAlias())) {
    t.adoptInstead(ures_getNextResource(bund->getAlias(), t.orphan(), status));
    ASSERT_SUCCESS(status, "while processing table");
@@ -254,10 +254,10 @@ int list(const char* toBundle) {
    printf("\"locale\": %s\n", locale);
  }

  LocalUResourceBundlePointer bund(
  icu::LocalUResourceBundlePointer bund(
      ures_openDirect(packageName.data(), locale, &status));
  ASSERT_SUCCESS(&status, "while opening the bundle");
  LocalUResourceBundlePointer installedLocales(
  icu::LocalUResourceBundlePointer installedLocales(
      // NOLINTNEXTLINE (readability/null_usage)
      ures_getByKey(bund.getAlias(), INSTALLEDLOCALES, NULL, &status));
  ASSERT_SUCCESS(&status, "while fetching installed locales");
@@ -295,7 +295,7 @@ int list(const char* toBundle) {
  }

  // OK, now list them.
  LocalUResourceBundlePointer subkey;
  icu::LocalUResourceBundlePointer subkey;

  int validCount = 0;
  for (int32_t i = 0; i < count; i++) {