Remove RAWCPP_FLAGS

Summary:
#9094 mentions to "remove the RAW_CPP bits from the ghc build system because
they're not longer needed", "once the CPP settings ticket is merged #8683"

#8683 was merged with 34f7e9a3, Phab:D26.

Test Plan: harbormaster

Reviewers: carter, austin

Reviewed By: austin

Subscribers: simonmar, ezyang, carter

Differential Revision: https://phabricator.haskell.org/D240

GHC Trac Issues: #9094

compiler/ghc.mk

@@ -263,10 +263,10 @@ compiler_CPP_OPTS += ${GhcCppOpts}
 define preprocessCompilerFiles
 # $0 = stage
 compiler/stage$1/build/Parser.y: compiler/parser/Parser.y.pp
-	$$(CPP) $$(RAWCPP_FLAGS) -P $$(compiler_CPP_OPTS) -x c $$< | grep -v '^#pragma GCC' > $$@
+	$$(CPP) -P $$(compiler_CPP_OPTS) -x c $$< | grep -v '^#pragma GCC' > $$@
 
 compiler/stage$1/build/primops.txt: compiler/prelude/primops.txt.pp compiler/stage$1/$$(PLATFORM_H)
-	$$(CPP) $$(RAWCPP_FLAGS) -P $$(compiler_CPP_OPTS) -Icompiler/stage$1 -x c $$< | grep -v '^#pragma GCC' > $$@
+	$$(CPP) -P $$(compiler_CPP_OPTS) -Icompiler/stage$1 -x c $$< | grep -v '^#pragma GCC' > $$@
 
 compiler/stage$1/build/primop-data-decl.hs-incl: compiler/stage$1/build/primops.txt $$$$(genprimopcode_INPLACE)
 	"$$(genprimopcode_INPLACE)" --data-decl          < $$< > $$@

mk/config.mk.in

@@ -626,15 +626,6 @@ CP			= cp
 # It's not easy to separate the CPP program from its flags, as
 # AC_PROG_CPP defines CPP as "/usr/bin/gcc -E"
 CPP			= @CPP@ @CPPFLAGS@
-#
-# RAWCPP_FLAGS are the flags to give to cpp (viz, gcc -E) to persuade it to
-# behave plausibly on Haskell sources.
-#
-# Clang in particular is a bit more annoying, so we suppress some warnings.
-RAWCPP_FLAGS            = -undef -traditional
-ifeq "$(CC_CLANG_BACKEND)" "1"
-RAWCPP_FLAGS           += -Wno-invalid-pp-token -Wno-unicode -Wno-trigraphs
-endif
 
 FIND			= @FindCmd@
 

rules/manual-package-config.mk

@@ -16,7 +16,7 @@ $(call trace, manual-package-config($1))
 $(call profStart, manual-package-config($1))
 
 $1/dist/package.conf.inplace : $1/package.conf.in $$$$(ghc-pkg_INPLACE) | $$$$(dir $$$$@)/.
-	$$(CPP) $$(RAWCPP_FLAGS) -P \
+	$$(CPP) -P \
 		-DTOP='"$$(TOP)"' \
 		$$($1_PACKAGE_CPP_OPTS) \
 		-x c $$(addprefix -I,$$(GHC_INCLUDE_DIRS)) $$< -o $$@.raw
@@ -29,7 +29,7 @@ $1/dist/package.conf.inplace : $1/package.conf.in $$$$(ghc-pkg_INPLACE) | $$$$(d
 # "make install", so we declare it as phony
 .PHONY: $1/dist/package.conf.install
 $1/dist/package.conf.install: | $$$$(dir $$$$@)/.
-	$$(CPP) $$(RAWCPP_FLAGS) -P \
+	$$(CPP) -P \
 		-DINSTALLING \
 		-DLIB_DIR='"$$(if $$(filter YES,$$(RelocatableBuild)),$$$$topdir,$$(ghclibdir))"' \
 		-DINCLUDE_DIR='"$$(if $$(filter YES,$$(RelocatableBuild)),$$$$topdir,$$(ghclibdir))/include"' \