Fixes:
xercesc/util/XMLChTranscoder.cpp:73:23: warning: setting buffer to a 'sizeof' expression; did you mean to transpose the last two arguments? [-Wmemset-transposed-args]
    memset(charSizes, sizeof(XMLCh), countToDo);
                      ^
xercesc/util/XMLChTranscoder.cpp:73:23: note: cast the second argument to 'int' to silence

and

xercesc/util/XMLUTF16Transcoder.cpp:114:23: warning: setting buffer to a 'sizeof' expression; did you mean to transpose the last two arguments? [-Wmemset-transposed-args]
    memset(charSizes, sizeof(UTF16Ch), countToDo);
                      ^
xercesc/util/XMLUTF16Transcoder.cpp:114:23: note: cast the second argument to 'int' to silence
1 warning generated.

XERCESC-2219: XMLReader constructor: fix memory leak when refreshRawBuffer() throws

XERCESC-2218: CurlURLInputStream constructor: avoid memory leak

XERCESC-2217: ICUTranscoder::transcodeFrom(): fix read heap-buffer-overflow

Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=37529 on GDAL

The backtrace of the exception that caused the memory leak was:
```
Catchpoint 1 (exception thrown), 0x00007ffff5547672 in __cxa_throw () from /lib/x86_64-linux-gnu/libstdc++.so.6
(gdb) bt
0  0x00007ffff5547672 in __cxa_throw () from /lib/x86_64-linux-gnu/libstdc++.so.6
1  0x00007ffff24447c4 in xercesc_4_0::PosixFileMgr::fileRead (this=<optimized out>, f=<optimized out>, byteCount=<optimized out>, buffer=<optimized out>, manager=0x5555556df730)
   at xercesc/util/FileManagers/PosixFileMgr.cpp:160
2  0x00007ffff24e6ec2 in xercesc_4_0::XMLReader::refreshRawBuffer (this=0x5555557e49f8) at xercesc/internal/XMLReader.cpp:1891
3  0x00007ffff24e70d4 in xercesc_4_0::XMLReader::XMLReader (this=0x5555557e49f8, pubId=<optimized out>, sysId=0x555555750920 u"/", streamToAdopt=0x55555574e838, from=<optimized out>,
   type=xercesc_4_0::XMLReader::Type_General, source=xercesc_4_0::XMLReader::Source_External, throwAtEnd=false, calculateSrcOfs=false, lowWaterMark=100, version=xercesc_4_0::XMLReader::XMLV1_0,
   manager=0x5555556df730) at xercesc/internal/XMLReader.cpp:130
4  0x00007ffff24ced75 in xercesc_4_0::ReaderMgr::createReader (this=this@entry=0x5555557896d8, src=..., refFrom=refFrom@entry=xercesc_4_0::XMLReader::RefFrom_NonLiteral,
   type=type@entry=xercesc_4_0::XMLReader::Type_General, source=source@entry=xercesc_4_0::XMLReader::Source_External, calcSrcOfs=false, lowWaterMark=100) at ./xercesc/sax/InputSource.hpp:314
5  0x00007ffff24cb0af in xercesc_4_0::IGXMLScanner::scanReset (this=0x555555789608, src=...) at xercesc/internal/IGXMLScanner2.cpp:1286
6  0x00007ffff24c36e9 in xercesc_4_0::IGXMLScanner::scanDocument (this=0x555555789608, src=...) at xercesc/internal/IGXMLScanner.cpp:198
7  0x00007ffff250abaf in xercesc_4_0::AbstractDOMParser::parse (this=0x7fffffffc2d0, source=...) at xercesc/parsers/AbstractDOMParser.cpp:545
8  0x00007ffff24cbdbe in xercesc_4_0::IGXMLScanner::resolveSchemaGrammar (this=0x555555792f78, loc=0x5555557dd694 u"/", uri=0x555555737180 u"`", ignoreLoadSchema=<optimized out>)
   at xercesc/internal/IGXMLScanner2.cpp:1895
  0x00007ffff24cce7c in xercesc_4_0::IGXMLScanner::parseSchemaLocation (this=0x555555792f78, schemaLocationStr=<optimized out>, ignoreLoadSchema=false) at ./xercesc/framework/XMLBuffer.hpp:171
10 0x00007ffff24cd182 in xercesc_4_0::IGXMLScanner::scanRawAttrListforNameSpaces (this=this@entry=0x555555792f78, attCount=attCount@entry=9) at xercesc/internal/IGXMLScanner2.cpp:1649
11 0x00007ffff24c22cb in xercesc_4_0::IGXMLScanner::scanStartTagNS (this=0x555555792f78, gotData=@0x7fffffffc91f: true) at xercesc/internal/IGXMLScanner.cpp:2213
12 0x00007ffff24c3522 in xercesc_4_0::IGXMLScanner::scanContent (this=0x555555792f78) at xercesc/internal/IGXMLScanner.cpp:890
13 0x00007ffff24c3760 in xercesc_4_0::IGXMLScanner::scanDocument (this=0x555555792f78, src=...) at xercesc/internal/IGXMLScanner.cpp:217
14 0x00007ffff25158e3 in xercesc_4_0::SAX2XMLReaderImpl::parse (this=0x555555731828, source=...) at xercesc/parsers/SAX2XMLReaderImpl.cpp:409
```

ci: Travis uses XCode 12.5

CurlURLInputStream constructor calls the readMore() method, which can
throw exceptions. In that situation, the destructor is not called, which
results in resource/memory leaks. To fix that, catch the exceptions,
manually do the cleanup and rethrow the exceptions.

Found by ossfuzz (locally)

Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35373

When charsDecoded == 0, the line ``for (index = 0; index < charsDecoded
- 1; index++)`` will cause to read out of bounds of fSrcOffsets, due to
unsigned integer underflow rules.

Version 4.0.0

XERCESC-2209: Remove unused LSTRING feature test

XERCESC-2110: Remove XERCES_NO_MATCHING_DELETE_OPERATOR

XERCESC-2200: Appveyor bug fix

XERCESC-2201: Upgrade travis-ci

XERCESC-2141: Enable C++17, C++14 or C++11 when available

Use C++98 features and remove pre-Standard workarounds

XERCESC-2202: Update version to 3.3.0