MinGW-w64: Add guards for MSVC macro definitions

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CMakeLists.txt

@@ -476,6 +476,7 @@ if( CMAKE_C_COMPILER_ID MATCHES "MSVC")
 		#                                   in pcap-stdinc.h when compiling C++ files, e.g. the Qt UI
 		/DPSAPI_VERSION=1
 		/D_ALLOW_KEYWORD_MACROS
+		# Disable deprecation of POSIX function names.
 		# https://stackoverflow.com/questions/37845163/what-is-the-purpose-of-microsofts-underscore-c-functions
 		/D_CRT_NONSTDC_NO_WARNINGS
 	)

cmakeconfig.h.in

@@ -292,6 +292,9 @@
 #  if !defined(QT_VERSION) || !defined(_SSIZE_T_DEFINED)
    typedef int ssize_t;
 #  endif
+#  define strncasecmp strnicmp
+#  define popen       _popen
+#  define pclose      _pclose
 #endif
 
 #if defined(_WIN32)
@@ -305,10 +308,6 @@
     */
 #  define YY_NO_UNISTD_H
 
-#  define strncasecmp strnicmp
-#  define popen       _popen
-#  define pclose      _pclose
-
 #  ifndef __STDC__
 #    define __STDC__ 0
 #  endif