Remove some single-use build system variables

ghc.mk

@@ -587,24 +587,24 @@ endif
 # variables defined by their dependencies
 
 ifneq "$(BINDIST)" "YES"
-BUILD_DIRS += $(GHC_MKDIRHIER_DIR)
+BUILD_DIRS += utils/mkdirhier
 endif
 
 ifeq "$(Windows_Host)" "YES"
-BUILD_DIRS += $(GHC_TOUCHY_DIR)
+BUILD_DIRS += utils/touchy
 endif
 
 BUILD_DIRS += docs/users_guide
 BUILD_DIRS += docs/man
 BUILD_DIRS += $(GHC_UNLIT_DIR)
-BUILD_DIRS += $(GHC_HP2PS_DIR)
+BUILD_DIRS += utils/hp2ps
 
 ifneq "$(GhcUnregisterised)" "YES"
 BUILD_DIRS += $(GHC_SPLIT_DIR)
 endif
 
 ifneq "$(BINDIST)" "YES"
-BUILD_DIRS += $(GHC_GENPRIMOP_DIR)
+BUILD_DIRS += utils/genprimopcode
 endif
 
 BUILD_DIRS += driver
@@ -617,7 +617,7 @@ BUILD_DIRS += rts
 
 ifneq "$(BINDIST)" "YES"
 BUILD_DIRS += bindisttest 
-BUILD_DIRS += $(GHC_GENAPPLY_DIR)
+BUILD_DIRS += utils/genapply
 endif
 
 ifneq "$(CLEANING)" "YES"
@@ -644,8 +644,8 @@ endif
 BUILD_DIRS += utils/haddock
 BUILD_DIRS += utils/haddock/doc
 BUILD_DIRS += compiler
-BUILD_DIRS += $(GHC_HSC2HS_DIR)
-BUILD_DIRS += $(GHC_PKG_DIR)
+BUILD_DIRS += utils/hsc2hs
+BUILD_DIRS += utils/ghc-pkg
 BUILD_DIRS += utils/deriveConstants
 BUILD_DIRS += utils/testremove
 BUILD_DIRS += $(MAYBE_GHCTAGS)

mk/tree.mk

@@ -20,14 +20,7 @@ GHC_INCLUDE_DIRS        = includes includes/dist includes/dist-derivedconstants/
 GHC_RTS_DIR             = rts
 GHC_DRIVER_DIR          = driver
 
-GHC_MKDIRHIER_DIR       = $(GHC_UTILS_DIR)/mkdirhier
 GHC_UNLIT_DIR           = $(GHC_UTILS_DIR)/unlit
-GHC_HP2PS_DIR           = $(GHC_UTILS_DIR)/hp2ps
-GHC_HSC2HS_DIR          = $(GHC_UTILS_DIR)/hsc2hs
-GHC_TOUCHY_DIR          = $(GHC_UTILS_DIR)/touchy
-GHC_PKG_DIR             = $(GHC_UTILS_DIR)/ghc-pkg
-GHC_GENPRIMOP_DIR       = $(GHC_UTILS_DIR)/genprimopcode
-GHC_GENAPPLY_DIR        = $(GHC_UTILS_DIR)/genapply
 GHC_CABAL_DIR           = $(GHC_UTILS_DIR)/ghc-cabal
 GHC_SPLIT_DIR           = $(GHC_DRIVER_DIR)/split
 GHC_SYSMAN_DIR          = $(GHC_RTS_DIR)/parallel