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/character_decoder.cpp

@@ -288,7 +288,7 @@ 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/file.h

@@ -35,6 +35,7 @@
 #include <iterator>
 #include <map>
 #include <memory>
+#include <cstdint>
 
 #ifdef IFOPSH_WITH_ROCKSDB
 

src/ifcparse/instance_data.h

@@ -37,6 +37,11 @@
 
 #endif
 
+#include <cstdint>
+#include <cstring>
+
+#include <boost/optional.hpp>
+#include <boost/shared_ptr.hpp>
 #include <boost/logic/tribool.hpp>
 #include <boost/dynamic_bitset.hpp>
 

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/schema.h

@@ -26,8 +26,10 @@
 #include <algorithm>
 #include <boost/algorithm/string.hpp>
 #include <cctype>
+#include <cstdint>
 #include <iterator>
 #include <map>
+#include <memory>
 #include <string>
 #include <vector>
 #include <optional>

src/ifcparse/storage.h

@@ -33,6 +33,7 @@ namespace rocksdb {
 #include <iterator>
 #include <map>
 #include <memory>
+#include <cstring>
 #include <type_traits>
 #include <iostream>
 #include <deque>

src/ifcparse/variant_array.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 "exception.h"