use icerun to avoid compilation process explosions using icecream.

Change-Id: I3539bfcfbbb43f44a6fc8fae60bda84267938116

config_host.mk.in

@@ -254,6 +254,7 @@ export HUNSPELL_CFLAGS=@HUNSPELL_CFLAGS@
 export HUNSPELL_LIBS=@HUNSPELL_LIBS@
 export HYPHEN_LIB=@HYPHEN_LIB@
 export HYPH_SYSTEM_DIR=@HYPH_SYSTEM_DIR@
+export ICECREAM_RUN=@ICECREAM_RUN@
 export ICU_MAJOR=@ICU_MAJOR@
 export ICU_MICRO=@ICU_MICRO@
 export ICU_MINOR=@ICU_MINOR@

configure.in

@@ -12614,6 +12614,17 @@ fi
 AC_MSG_RESULT([$BUILD_MAX_JOBS])
 AC_SUBST(BUILD_MAX_JOBS)
 
+dnl ===================================================================
+dnl icerun is a wrapper that stops us spawning tens of processes
+dnl locally - for tools that can't be executed on the compile cluster
+dnl this avoids a dozen javac's ganging up on your laptop to kill it.
+dnl ===================================================================
+ICECREAM_RUN=
+if test "$enable_icecream" = "yes"; then
+   ICECREAM_RUN=icerun
+fi
+AC_SUBST(ICECREAM_RUN)
+
 # =====================================================================
 # determine the parallelism for gnu make
 # =====================================================================

solenv/gbuild/JavaClassSet.mk

@@ -26,7 +26,7 @@
 #
 #*************************************************************************
 
-gb_JavaClassSet_JAVACCOMMAND := $(JAVACOMPILER) $(JAVAFLAGS) \
+gb_JavaClassSet_JAVACCOMMAND := $(ICECREAM_RUN) $(JAVACOMPILER) $(JAVAFLAGS) \
     -source $(JAVA_SOURCE_VER) -target $(JAVA_TARGET_VER)
 gb_JavaClassSet_JAVACDEBUG :=