Add missing standard library includes for self-sufficient headers

Fixes builds with newer GCC/libstdc++ that no longer provide <cstdint>,
<cstring>, <cfloat>, <memory>, <algorithm> etc. transitively. Also
disambiguates visit<> calls in taxonomy.h with the full namespace and
casts the character value in IfcCharacterDecoder to uint32_t to silence
ambiguous overload warnings.

src/ifcparse/IfcBaseClass.h

@@ -27,6 +27,7 @@
 #include "utils.h"
 
 #include <atomic>
+#include <cstdint>
 #include <boost/shared_ptr.hpp>
 
 class aggregate_of_instance;

src/ifcparse/IfcCharacterDecoder.cpp

@@ -201,7 +201,7 @@ namespace {
                 if (character >= 0x20 && character <= 0x7e) {
                     stream.put((char)character);
                 } else {
-                    stream << "\\u" << character;
+                    stream << "\\u" << static_cast<uint32_t>(character);
                 }
             });
             return stream.str();

src/ifcparse/IfcEntityInstanceData.h

@@ -36,6 +36,9 @@
 
 #endif
 
+#include <cstdint>
+#include <cstring>
+
 #include <boost/optional.hpp>
 #include <boost/shared_ptr.hpp>
 #include <boost/logic/tribool.hpp>

src/ifcparse/IfcFile.h

@@ -34,6 +34,7 @@
 #include <boost/circular_buffer.hpp>
 #include <iterator>
 #include <map>
+#include <cstdint>
 
 #ifdef IFOPSH_WITH_ROCKSDB
 #include <rocksdb/merge_operator.h>

src/ifcparse/IfcSchema.h

@@ -25,7 +25,9 @@
 #include <algorithm>
 #include <boost/algorithm/string.hpp>
 #include <cctype>
+#include <cstdint>
 #include <iterator>
+#include <memory>
 #include <string>
 #include <vector>
 

src/ifcparse/aggregate_of_instance.h

@@ -26,6 +26,7 @@
 #include <boost/shared_ptr.hpp>
 #include <set>
 #include <vector>
+#include <algorithm>
 
 namespace IfcParse {
     class declaration;

src/ifcparse/rocksdb_map_adapter.h

@@ -30,6 +30,8 @@
 #include <utility>
 #include <iterator>
 #include <cstddef>
+#include <cstdint>
+#include <cstring>
 
 template <typename T>
 struct is_std_tuple : std::false_type {};

src/ifcparse/storage.h

@@ -25,6 +25,8 @@ namespace rocksdb {
 
 #include <variant>
 #include <iterator>
+#include <cstdint>
+#include <cstring>
 #include <type_traits>
 #include <iostream>
 #include <vector>

src/ifcparse/variantarray.h

@@ -33,6 +33,10 @@ variant - which is the maximum size of its constituents - is reduced.
 #include <utility>
 #include <memory>
 #include <tuple>
+#include <cstdint>
+#include <cstring>
+#include <cstddef>
+#include <limits>
 
 #include "IfcException.h"