MinGW-w64 Utils:: compilation fix

The include for utils/environment.h was omitted
unless Q_OS_MSVC, but the code that uses it is
also compiled for MinGW-w64, so change that compile
guard to Q_OS_WIN instead.

Change-Id: I2fa5a09f1864c0ed38d09e3fbb2c6f661fbc8b26
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

tests/auto/debugger/tst_dumpers.cpp

@@ -33,12 +33,14 @@
 #include "watchdata.h"
 #include "watchutils.h"
 
-#ifdef Q_CC_MSVC
+#ifdef Q_OS_WIN
 #include <utils/environment.h>
+#ifdef Q_CC_MSVC
 #include <utils/qtcprocess.h>
 #include <utils/fileutils.h>
 #include <utils/synchronousprocess.h>
 #endif // Q_CC_MSVC
+#endif // Q_OS_WIN
 
 #include <QtTest>
 #include <math.h>