fix: try fix clang libcxx charconv issue.

- add compile checker in cmake to detect charconv support status.
- and expose macro for yycc to enable different part of charconv repectively to prevent duplicated defines.

cmake/check_charconv/to_chars_int.cpp

@@ -0,0 +1,41 @@
+#include <charconv>
+#include <cstdint>
+
+int main(int argc, char **argv) {
+    char buffer[1024];
+    char* first = buffer;
+    char* last = first + sizeof(buffer);
+
+    {
+        std::int8_t value = 0;
+        auto rv = std::to_chars(first, last, value, 10);
+    }
+    {
+        std::int16_t value = 0;
+        auto rv = std::to_chars(first, last, value, 10);
+    }
+    {
+        std::int32_t value = 0;
+        auto rv = std::to_chars(first, last, value, 10);
+    }
+    {
+        std::int64_t value = 0;
+        auto rv = std::to_chars(first, last, value, 10);
+    }
+    {
+        std::uint8_t value = 0;
+        auto rv = std::to_chars(first, last, value, 10);
+    }
+    {
+        std::uint16_t value = 0;
+        auto rv = std::to_chars(first, last, value, 10);
+    }
+    {
+        std::uint32_t value = 0;
+        auto rv = std::to_chars(first, last, value, 10);
+    }
+    {
+        std::uint64_t value = 0;
+        auto rv = std::to_chars(first, last, value, 10);
+    }
+}