Fix bat-script generation for MSys

The bat-script generation was using the wrong paths, in
	ghc-inplace
	ghc-pkg
	hsc2hs
plus there was a double-backslah in the latter two which was wrong.
This patch fixes both.  See "MSys Note 3" in compiler/Makefile

compiler/Makefile

@@ -727,7 +727,7 @@ else
 SCRIPT_SHELL = /bin/sh
 endif
 
-# Note 2
+# MSys Note 2
 # On MSys, we must use the following script for ghc-inplace:
 #   exec /c/darcs/fc-branch-2/compiler/stage1/ghc -Bc:/darcs/fc-branch-2 "$@"
 # That is, 
@@ -748,10 +748,16 @@ $(odir)/ghc-inplace : $(GHC_PROG)
 # Re exec, see note 2 above
 	chmod 755 $@
 
+# MSys Note 3
+# When we generate a .bat file, we must also use the form
+#	@call c:\darcs\fc-branch-2\compiler\stage1\ghc-inplace
+# else the cmd shell gets confused; indeed it seems to simply hang
+# Hence the use of $(FPTOOLS_TOP_ABS_PLATFORM) here, just like MSys Note 2
+
 ifeq "$(TARGETPLATFORM)" "i386-unknown-mingw32"
 ghc-inplace.bat $(odir)/ghc-inplace.bat: $(GHC_PROG)
 	@$(RM) $@
-	echo '@call $(subst /,\,$(GHC_COMPILER_DIR_ABS)/$(GHC_PROG)) -B$(FPTOOLS_TOP_ABS_PLATFORM) %*' >> $@
+	echo '@call $(subst /,\,$(FPTOOLS_TOP_ABS_PLATFORM)/$(GHC_COMPILER_DIR_REL)/$(GHC_PROG)) -B$(FPTOOLS_TOP_ABS_PLATFORM) %*' >> $@
 	chmod 755 $@
 endif	
 

utils/ghc-pkg/Makefile

@@ -105,8 +105,9 @@ endif
 ifeq "$(INSTALLING)$(HOSTPLATFORM)" "0i386-unknown-mingw32"
 all :: $(INPLACE_SCRIPT_PROG).bat
 
+# See "MSys Note 3" in compiler/Makefile
 $(INPLACE_SCRIPT_PROG).bat :
-	echo '@call $(subst /,\\,$(FPTOOLS_TOP_ABS)/utils/ghc-pkg/$(HS_PROG)) --global-conf $(PKGCONF) %*' >> $@
+	echo '@call $(subst /,\,$(FPTOOLS_TOP_ABS_PLATFORM)/utils/ghc-pkg/$(HS_PROG)) --global-conf $(PKGCONF) %*' >> $@
 	chmod 755 $@
 endif
 

utils/hsc2hs/Makefile

@@ -98,7 +98,8 @@ endif
 ifeq "$(INSTALLING)$(HOSTPLATFORM)" "0i386-unknown-mingw32"
 all :: $(INPLACE_SCRIPT_PROG).bat
 
-FULL_INPLACE_PATH=$(subst /,\\,$(FPTOOLS_TOP_ABS)/utils/hsc2hs/)
+# See "MSys Note 3" in compiler/Makefile
+FULL_INPLACE_PATH=$(subst /,\,$(FPTOOLS_TOP_ABS_PLATFORM)/utils/hsc2hs/)
 $(INPLACE_SCRIPT_PROG).bat :
 	echo '@call $(FULL_INPLACE_PATH)$(HS_PROG) --template=$(FULL_INPLACE_PATH)template-hsc.h $(HSC2HS_EXTRA) %*' >> $@
 	chmod 755 $@