Mac: Remove invalid bundle identifier characters

Valid characters are (A-Z,a-z,0-9,-,.).

It is unlikely that we will see anything more exotic
than '_' in bundle/library names, go ahead and replace
that character only.

Task-number: QTBUG-46824
Change-Id: Ia97b7cd6247f40a970b4919363ffb66fb347186c
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@theqtcompany.com>

qmake/generators/unix/unixmake2.cpp

@@ -840,6 +840,8 @@ UnixMakefileGenerator::writeMakeParts(QTextStream &t)
                 bundleIdentifier.chop(4);
             if (bundleIdentifier.endsWith(".framework"))
                 bundleIdentifier.chop(10);
+            // replace invalid bundle id characters
+            bundleIdentifier.replace('_', '-');
             commonSedArgs << "-e \"s,@BUNDLEIDENTIFIER@," << bundleIdentifier << ",g\" ";
 
             if (isApp) {