new C preprocessor breaks ghc's build process

bash-2.03$ cat old
infix 5 \\

bash-2.03$ cat -vet old
infix 5 \\ $
$
bash-2.03$ cat new
infix 5 \\ --

bash-2.03$ cpp-2.95 old
# 1 "old"
infix 5 \\

bash-2.03$ cpp-2.95 new
# 1 "new"
infix 5 \\ --

bash-2.03$ cpp-3.4.1 old
# 1 "old"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "old"
old:1:10: warning: backslash and newline separated by
space
infix 5 \
bash-2.03$ cpp-3.4.1 new
# 1 "new"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "new"
infix 5 \\ --
bash-2.03$

The new behavior is documented in cpp.info of the
gcc-3.4.1 distribution.
Line 212 of ghc-6.2.1/libraries/base/Data/List.hs
expects the old behavior.

Trac metadata

Trac field	Value
Version	None
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	ResolvedFixed
Component	libraries/base
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture