Remove ghc-7.8 `-package-name`-compat handling

This code was introduced in 66218d15 to
use `-package-name` for GHC 7.8, whereas GHC 7.10 needs the new
`-this-package-key` flag.

configure.ac

@@ -159,11 +159,6 @@ FP_COMPARE_VERSIONS([$GhcVersion],[-gt],[7.7],
                     CMM_SINK_BOOTSTRAP_IS_NEEDED=NO)
 AC_SUBST(CMM_SINK_BOOTSTRAP_IS_NEEDED)
 
-FP_COMPARE_VERSIONS([$GhcVersion],[-lt],[7.9],
-                    SUPPORTS_COMPONENT_ID=NO,
-                    SUPPORTS_COMPONENT_ID=YES)
-AC_SUBST(SUPPORTS_COMPONENT_ID)
-
 # GHC is passed to Cabal, so we need a native path
 if test "${WithGhc}" != ""
 then

mk/config.mk.in

@@ -500,8 +500,6 @@ GHC_PACKAGE_DB_FLAG = @GHC_PACKAGE_DB_FLAG@
 
 CMM_SINK_BOOTSTRAP_IS_NEEDED = @CMM_SINK_BOOTSTRAP_IS_NEEDED@
 
-SUPPORTS_COMPONENT_ID = @SUPPORTS_COMPONENT_ID@
-
 #-----------------------------------------------------------------------------
 # C compiler
 #

rules/distdir-way-opts.mk

@@ -96,21 +96,9 @@ define distdir-way-opts # args: $1 = dir, $2 = distdir, $3 = way, $4 = stage
 # $1_$2_$3_MOST_HC_OPTS is also passed to C compilations when we use
 # GHC as the C compiler.
 
-ifeq "$(SUPPORTS_COMPONENT_ID)" "NO"
-ifeq "$4" "0"
-$4_USE_COMPONENT_ID=NO
-endif
-endif
-
 $1_$2_$4_DEP_OPTS = \
  $$(foreach pkg,$$($1_$2_DEP_IPIDS),-package-id $$(pkg))
 
-ifeq "$($4_USE_COMPONENT_ID)" "NO"
-$4_THIS_COMPONENT_ID = -package-name
-else
-$4_THIS_COMPONENT_ID = -this-package-key
-endif
-
 $1_$2_$3_MOST_HC_OPTS = \
  $$(WAY_$3_HC_OPTS) \
  $$(CONF_HC_OPTS) \
@@ -119,7 +107,7 @@ $1_$2_$3_MOST_HC_OPTS = \
  $$($1_HC_OPTS) \
  $$($1_$2_HC_PKGCONF) \
  $$(if $$($1_$2_PROG),, \
-        $$(if $$($1_PACKAGE),$$($4_THIS_COMPONENT_ID) $$($1_$2_COMPONENT_ID))) \
+        $$(if $$($1_PACKAGE),-this-package-key $$($1_$2_COMPONENT_ID))) \
  $$(if $$($1_PACKAGE),-hide-all-packages) \
  -i $$(if $$($1_$2_HS_SRC_DIRS),$$(foreach dir,$$($1_$2_HS_SRC_DIRS),-i$1/$$(dir)),-i$1) \
  -i$1/$2/build -i$1/$2/build/autogen \