regen-makefile: Use '-U 5' to split C++ files in multiple chunks

Particularly the C++ files generated for the rather comprehensive
3GPP asn.1 specified protocols like MAP, RANAP, ... result in very
large source files and subsequently g++ processes that consume well
into the multiple gigabyte range of memory.

Let's use the '-U 5' option to ask the ttcn3_compiler to split all
c++ files into 5 chunks, resulting in more files to compile, but
smaller individual files.

I also tested '-U type' before, but it was still grinding my 16GB RAM
laptop to unusable deep-swapping state when running 'make -j8' for
the IuCS extended MSC test suite.

Change-Id: I013b623e98d58a39dd7bb2b0db4a911725028535
diff --git a/regen-makefile.sh b/regen-makefile.sh
index 77fcb6c..d2b747e 100755
--- a/regen-makefile.sh
+++ b/regen-makefile.sh
@@ -24,7 +24,7 @@
 	USE_CCACHE=1
 fi
 
-ttcn3_makefilegen -p -l -f $*
+ttcn3_makefilegen -p -l -U 5 -f $*
 
 TITAN_VERSION=$(ttcn3_makefilegen -v 2>&1 |grep "Product number" |cut --delimiter="/" -f 2-| sed -e "s/[A-Z ]//g")
 
@@ -60,5 +60,5 @@
 	sed -i -e 's/^CXX = g++ $/CXX = env CCACHE_SLOPPINESS=time_macros ccache g++/' Makefile
 	# Append the -D option to compiler flags. This option disables timestamps
 	# inside comments in the generated C++ code which interfere with ccache.
-	sed -i -e 's/^COMPILER_FLAGS = \(.*\)/&-D/' Makefile
+	sed -i -e 's/^COMPILER_FLAGS = \(.*\)/& -D/' Makefile
 fi