Fix build on Mac.

src/libs/utils/environment.cpp

@@ -176,22 +176,17 @@ void Environment::prependOrSetPath(const QString &value)
 
 void Environment::prependOrSetLibrarySearchPath(const QString &value)
 {
-#ifdef Q_OS_WIN
+#ifdef Q_OS_MAC
+    // we could set DYLD_LIBRARY_PATH on Mac but it is unnecessary in practice
+#elif Q_OS_WIN
     const QChar sep = QLatin1Char(';');
-#else
-    const QChar sep = QLatin1Char(':');
-#endif
-
-#ifdef Q_OS_WIN
     const QLatin1String path("PATH");
-#elif defined(Q_OS_UNIX) && !defined(Q_OS_MAC)
+    prependOrSet(path, QDir::toNativeSeparators(value), QString(sep));
+#elif Q_OS_UNIX
+    const QChar sep = QLatin1Char(':');
     const QLatin1String path("LD_LIBRARY_PATH");
-#else
-    // we could set DYLD_LIBRARY_PATH on Mac but it is unnecessary in practice
-    return;
-#endif
-
     prependOrSet(path, QDir::toNativeSeparators(value), QString(sep));
+#endif
 }
 
 Environment Environment::systemEnvironment()