Enable dynamic-by-default for unregisterised arches

This makes ghci work on platforms without any special support in the
GHCi linker:

Prelude> (System.Info.os, System.Info.arch)
("linux","s390")

1 files changed, 11 insertions, 11 deletions

diff --git a/mk/config.mk.in b/mk/config.mk.in
index 65a595729b..bc85bd479f 100644
--- a/mk/config.mk.in
+++ b/mk/config.mk.in
@@ -132,21 +132,21 @@ endif
 PlatformSupportsSharedLibs = $(if $(filter $(TARGETPLATFORM),\
 	$(SharedLibsPlatformList)),YES,NO)
 
-SharedLibsByDefaultPlatformList =               \
-                         x86_64-unknown-linux   \
-                         x86_64-apple-darwin
-
-# DYANMIC_BY_DEFAULT says whether this compiler will default to
+# DYNAMIC_BY_DEFAULT says whether this compiler will default to
 # building dynamic executables, i.e. -dynamic is on.  We do this for
-# certain platforms because it lets us use the system dynamic linker
+# most platforms because it lets us use the system dynamic linker
 # instead of our own linker for GHCi.
 #
-# We do not enable this for an unregisterised build.  It is currently
-# unknown whether shared libraries (should) work when unregisterised.
+# Currently this isn't possible on Windows, and we have not yet enabled
+# it on i386 while we consider the performance implications.
 #
-DYNAMIC_BY_DEFAULT = $(strip $(if $(filter YES,$(GhcUnregisterised)),NO,\
-			  $(if $(filter $(TARGETPLATFORM),\
-				$(SharedLibsByDefaultPlatformList)),YES,NO)))
+ifeq "$(TargetOS_CPP)" "mingw32"
+DYNAMIC_BY_DEFAULT = NO
+else ifeq "$(TargetArch_CPP)" "i386"
+DYNAMIC_BY_DEFAULT = NO
+else
+DYNAMIC_BY_DEFAULT = YES
+endif
 
 # Build a compiler that will build *unregisterised* libraries and
 # binaries by default.  Unregisterised code is supposed to compile and