https://issues.apache.org/jira/browse/XERCESC-2195

https://issues.apache.org/jira/browse/XERCESC-2214

https://issues.apache.org/jira/browse/XERCESC-2242

Mark Dependencies as `PRIVATE` in CMake

Fixes https://issues.apache.org/jira/browse/XERCESC-2236, where trying
to use the generated CMake config package doesn't work because the
dependencies are not loaded using find_package in the config package.
This change assumes they're not necessary for users of the library and
marks them as PRIVATE so they don't end up in the config package in the
first place.

[XERCESC-2235] DFAContentModel::buildDFA(): correctly zero-initialize fFollowList

Due to a copy&paste issue, the intended zero-initialization of
fFollowList wasn't done (copy&paste issue), and thus in case of
OutOfMemory exception when initializing the array, the memory freeing in
cleanup() could access uninitialized elements.

Follow-up of https://github.com/apache/xerces-c/pull/40 / a65990d7

Fixes GDAL's https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=42636

[XERCESC-2230] DFAContentModel::buildSyntaxTree(): fix memory leaks when OutOfMemoryException occurs

Fixes GDAL's https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=40866

[XERCESC-2229] IGXMLScanner::scanDocTypeDecl(): fix memory leak on exception

The method can leak pubId and sysId when subsequent call to
fReaderMgr.skipPastSpaces() throws an exception (e.g. a
TranscodingException)

[XERCESC-2228] DFAContentModel: fix memory leaks when OutOfMemoryException occurs

[XERCESC-2227] Memleak fixes in ContentSpecNode and ComplexTypeInfo classes

XERCESC-2208: XMLSize_t size_t revert

ComplexTypeInfo::expandContentModel(): restore use of retNode as in original code (this is equivalent)

Fixes GDAL's https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=39159

XERCESC-2208: Use cstdint and standard integer types

XERCESC-2226: Update minimum CMake version to 3.12

* Required for CURL imported target usage in XERCESC-2225
* Drop old cmake_policy settings which are now the default behaviour

XERCESC-2225: Link to installed CMake targets of CURL

[XERCESC-2224] DFAContentModel::checkUniqueParticleAttribution (): speed enhancement

The complexity of this method is roughly O(n^3). Fuzzers can generate
schemas with n = several thousands. The test fTransTable[i][j] == XMLContentModel::gInvalidTrans
is independant of the k loop, and can thus being moved at a upper level
to improve runtime.

[XERCESC-2223] SAX2XMLReaderImpl::error(): use exception memory manager, …

SAX2XMLReaderImpl::error(): use exception memory manager, otherwise regular memory manager might fail to fully allocate the strings in the exception and cause memory leaks

[XERCESC-2222] DFAContentModel::checkUniqueParticleAttribution(): fix memory leak

If a memory allocation of conflictTable[] fails, or later in the
function, the array is not freed.
Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=38533

Fix -Wmemset-transposed-args warnings of clang++

XERCESC-2221: InMemMsgLoader::loadMsg(): fix memory leak when transcoding fails.

Just like how it was done for ICU