fix(Data/SQLParser): restore Windows unistd guard in flex_lexer.cpp too #5377

e23f9a1 patched the same guard in flex_lexer.h but missed the
matching include in flex_lexer.cpp:3184, which also fails to compile
on clang-cl Windows. Apply the identical conditional in the .cpp.
Same caveat as before: lives in the generated file, must be
re-applied after every flex regen.

Author: aleks-f

Data/SQLParser/src/parser/flex_lexer.cpp

@@ -3181,8 +3181,17 @@ static thread_local std::stringstream strbuf;
  * down here because we want the user's section 1 to have been scanned first.
  * The user has a chance to override it with an option.
  */
+/* POCO-LOCAL: io.h provides the POSIX-ish I/O declarations flex's runtime
+ * uses (read/write/isatty/close) on MSVC; unistd.h does not exist there.
+ * Re-apply this conditional after every flex regen - it lives in the
+ * generated file, not in flex_lexer.l.
+ */
+#if defined(_WIN32) || defined(_WIN64)
+	#include <io.h>
+#else
 #include <unistd.h>
 #endif
+#endif
 
 #ifndef YY_EXTRA_TYPE
 #define YY_EXTRA_TYPE void *