[llvm] Conditionally include target intrinsics, based on --enable-target

Makefile.rules

Index: Makefile.rules
===================================================================
--- Makefile.rules	(revision 138929)
+++ Makefile.rules	(working copy)
@@ -258,6 +258,9 @@
   endif
 endif
 
+CPP.Defines += $(patsubst %,-DTARGET_ENABLED_%,\
+	$(shell echo $(TARGETS_TO_BUILD) | tr a-z A-Z))
+
 ifeq ($(ENABLE_PROFILING),1)
   BuildMode := $(BuildMode)+Profile
   CXX.Flags := $(filter-out -fomit-frame-pointer,$(CXX.Flags)) -pg -g
@@ -694,13 +697,18 @@
 ScriptInstall = $(INSTALL) -m 0755
 DataInstall   = $(INSTALL) -m 0644
 
+# Tell TableGen which targets were enabled to do additional filtering.
+TABLEGEN_TARGET_FLAGS = $(patsubst %,-DTARGET_%,\
+	$(shell echo $(TARGETS_TO_BUILD) | tr a-z A-Z))
+
 # When compiling under Mingw/Cygwin, the tblgen tool expects Windows
 # paths. In this case, the SYSPATH function (defined in
 # Makefile.config) transforms Unix paths into Windows paths.
 TableGen      = $(TBLGEN) -I $(call SYSPATH, $(PROJ_SRC_DIR)) \
                 -I $(call SYSPATH, $(LLVM_SRC_ROOT)/include) \
                 -I $(call SYSPATH, $(PROJ_SRC_ROOT)/include) \
-                -I $(call SYSPATH, $(PROJ_SRC_ROOT)/lib/Target)
+                -I $(call SYSPATH, $(PROJ_SRC_ROOT)/lib/Target) \
+                $(TABLEGEN_TARGET_FLAGS)
 
 Archive       = $(AR) $(AR.Flags)
 LArchive      = $(LLVMToolDir)/llvm-ar rcsf