lang/phantomjs: unbreak with ICU 59.1

API/JSStringRef.cpp:40:12: error: no matching function for call to 'create'

return OpaqueJSString::create(chars, numChars).leakRef();
       ^~~~~~~~~~~~~~~~~~~~~~

API/OpaqueJSString.h:44:39: note: candidate function not viable: no known conversion from 'const JSChar *' (aka 'const unsigned short *') to 'const LChar *' (aka 'const unsigned char *') for 1st argument

static PassRefPtr<OpaqueJSString> create(const LChar* characters, unsigned length)
                                  ^

API/OpaqueJSString.h:49:39: note: candidate function not viable: no known conversion from 'const JSChar *' (aka 'const unsigned short *') to 'const UChar *' (aka 'const char16_t *') for 1st argument

static PassRefPtr<OpaqueJSString> create(const UChar* characters, unsigned length)
                                  ^

API/OpaqueJSString.h:39:39: note: candidate function not viable: requires 0 arguments, but 2 were provided

static PassRefPtr<OpaqueJSString> create() // null
                                  ^

API/OpaqueJSString.h:54:57: note: candidate function not viable: requires 1 argument, but 2 were provided

JS_EXPORT_PRIVATE static PassRefPtr<OpaqueJSString> create(const String&);
                                                    ^

API/JSStringRef.cpp:65:35: error: no matching function for call to 'createWithoutCopying'

return OpaqueJSString::create(StringImpl::createWithoutCopying(chars, numChars, WTF::DoesNotHaveTerminatingNullCharacter)).leakRef();
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

../WTF/wtf/text/StringImpl.h:431:57: note: candidate function not viable: no known conversion from 'const JSChar *' (aka 'const unsigned short *') to 'const UChar *' (aka 'const char16_t *') for 1st argument

WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> createWithoutCopying(const UChar* characters, unsigned length, HasTerminatingNullCharacter);
                                                    ^

../WTF/wtf/text/StringImpl.h:432:57: note: candidate function not viable: no known conversion from 'const JSChar *' (aka 'const unsigned short *') to 'const LChar *' (aka 'const unsigned char *') for 1st argument

WTF_EXPORT_STRING_API static PassRefPtr<StringImpl> createWithoutCopying(const LChar* characters, unsigned length, HasTerminatingNullCharacter);
                                                    ^

API/JSStringRef.cpp:86:12: error: cannot initialize return object of type 'const JSChar *' (aka 'const unsigned short *') with an rvalue of type 'const UChar *' (aka 'const char16_t *')

return string->characters();
       ^~~~~~~~~~~~~~~~~~~~

PR: 222222
Obtained from: upstream (WebKit, rebased)