Clang: Rename directory ipcsource to source

Now it's in accordance with clangrefactoringbackend/source and
clangpchmanagerbackend/source.

Change-Id: I939cfc72cffb8fcde0649f125e6efb6670d1cbc3
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/tools/clangbackend/clangbackend.pro

@@ -4,7 +4,7 @@ QTC_LIB_DEPENDS += \
 
 include(../../qtcreatortool.pri)
 include(../../shared/clang/clang_installation.pri)
-include(ipcsource/clangbackendclangipc-source.pri)
+include(source/clangbackendclangipc-source.pri)
 
 QT += core network
 QT -= gui

src/tools/clangbackend/clangbackend.qbs

@@ -7,7 +7,7 @@ QtcTool {
     Depends { name: "libclang"; required: false }
 
     Group {
-        prefix: "ipcsource/"
+        prefix: "source/"
         files: [
             "*.h",
             "*.cpp"
@@ -26,7 +26,7 @@ QtcTool {
 
     condition: libclang.present
 
-    cpp.includePaths: base.concat(["ipcsource", libclang.llvmIncludeDir])
+    cpp.includePaths: base.concat(["source", libclang.llvmIncludeDir])
     cpp.libraryPaths: base.concat(libclang.llvmLibDir)
     cpp.dynamicLibraries: base.concat(libclang.llvmLibs)
     cpp.rpaths: base.concat(libclang.llvmLibDir)