Utils: Merge {synchronous,qtc}process.{h,cpp} file pairs

Mechanical to prepare merging the actual classes.
Adapting #includes.

Change-Id: I77a2c28129287778bc870c30cb890cd26bc2e62b
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/git/gerrit/gerritserver.cpp

@@ -31,8 +31,9 @@
 
 #include <coreplugin/icore.h>
 #include <coreplugin/shellcommand.h>
+
 #include <utils/hostosinfo.h>
-#include <utils/synchronousprocess.h>
+#include <utils/qtcprocess.h>
 
 #include <QFile>
 #include <QJsonDocument>

src/plugins/git/gitclient.cpp

@@ -50,7 +50,6 @@
 #include <utils/qtcassert.h>
 #include <utils/qtcprocess.h>
 #include <utils/stringutils.h>
-#include <utils/synchronousprocess.h>
 #include <utils/temporaryfile.h>
 #include <utils/theme/theme.h>
 

src/plugins/git/gitgrep.cpp

@@ -39,8 +39,8 @@
 #include <utils/filesearch.h>
 #include <utils/fileutils.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 #include <utils/runextensions.h>
-#include <utils/synchronousprocess.h>
 #include <utils/textfileformat.h>
 
 #include <QCheckBox>