Merged PR 6147892: Make til::feature build in the OS

This commit makes the feature staging header build in OS razzle.

Retrieved from https://microsoft.visualstudio.com os.2020 OS official/rs_wdx_dxp_windev cd1428ce557238663b7a748763ea8ce082b88256

Related work items: MSFT-33722503

src/dirs

@@ -1,4 +1,5 @@
 DIRS=\
+     staging \
      buffer \
      interactivity \
      dep \

src/project.inc

@@ -37,6 +37,8 @@ USER_C_FLAGS            = $(USER_C_FLAGS) /utf-8
 CONSOLE_SRC_PATH        = $(PROJECT_ROOT)\core\console\open\src
 CONSOLE_OBJ_PATH        = $(WINCORE_OBJ_PATH)\console\open\src
 
+USER_C_FLAGS            = $(USER_C_FLAGS) /FI$(CONSOLE_OBJ_PATH)\staging\$(O)\TilFeatureStaging.h
+
 INCLUDES= \
     $(INCLUDES); \
     $(CONSOLE_SRC_PATH)\inc; \

src/staging/makefile.inc

@@ -0,0 +1,3 @@
+$(OBJ_PATH)\$(O)\TilFeatureStaging.h: ..\features.xml
+	set BUILDMSG=Building til::feature flag header...
+	powershell -NoLogo -NoProfile -NonInteractive -ExecutionPolicy ByPass -Command ..\..\tools\Generate-FeatureStagingHeader.ps1 "$**" -Branding WindowsInbox -Branch $(BUILDBRANCH) -OutputPath "$@"

src/staging/sources

@@ -0,0 +1,7 @@
+_NEED_BUILDBRANCH=1
+TARGETTYPE=NOTARGET
+
+NTTARGETFILE0=\
+    $(OBJ_PATH)\$(O)\TilFeatureStaging.h
+
+# See build rules in makefile.inc