fix dependencies for generated headers from TYPELIBS

Dependencies to all header files generated by dumpcpp are now added to
every object file. This fixes parallel builds of projects that use
TYPELIBS.

Change-Id: I3c0456c7b182a42296ec6999aa86d1293ffd2e42
Task-number: QTBUG-45118
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>

mkspecs/features/win32/dumpcpp.prf

@@ -19,3 +19,17 @@ dumpcpp_impl.name = CPP
 dumpcpp_impl.depends = ${QMAKE_FILE_BASE}.h
 
 QMAKE_EXTRA_COMPILERS += dumpcpp_impl
+
+
+# Create dependencies from every object file to our generated header files.
+if(isEmpty(BUILDS)|build_pass):have_target:!contains(TEMPLATE, vc.*) {
+    for(tlb, TYPELIBS) {
+        hdr = $$basename(tlb)
+        hdr = $$section(hdr, ., 0, -2).h
+        TYPELIB_HEADERS += $$hdr
+    }
+
+    objtgt.target = $(OBJECTS)
+    objtgt.depends = $$TYPELIB_HEADERS
+    QMAKE_EXTRA_TARGETS += objtgt
+}