Add some more host tools

ifndef HOSTCXX

HOSTCXX:=g++

endif

ifndef HOSTCPP

HOSTCPP:=cpp

endif

ifndef HOSTLD

HOSTLD:=ld

endif

ifndef HOSTLN

HOSTLN:=ln

endif

ifndef HOSTNM

HOSTNM:=nm

endif

HOSTAR:=$(shell $(CONFIG_SHELL) -c "which $(HOSTAR)" || type -p $(HOSTAR) || echo ar)

HOSTAS:=$(shell $(CONFIG_SHELL) -c "which $(HOSTAS)" || type -p $(HOSTAS) || echo as)

HOSTCC:=$(shell $(CONFIG_SHELL) -c "which $(HOSTCC)" || type -p $(HOSTCC) || echo gcc)

HOSTCXX:=$(shell $(CONFIG_SHELL) -c "which $(HOSTCXX)" || type -p $(HOSTCXX) || echo g++)

HOSTCPP:=$(shell $(CONFIG_SHELL) -c "which $(HOSTCPP)" || type -p $(HOSTCPP) || echo cpp)

HOSTLD:=$(shell $(CONFIG_SHELL) -c "which $(HOSTLD)" || type -p $(HOSTLD) || echo ld)

HOSTLN:=$(shell $(CONFIG_SHELL) -c "which $(HOSTLN)" || type -p $(HOSTLN) || echo ln)

HOSTNM:=$(shell $(CONFIG_SHELL) -c "which $(HOSTNM)" || type -p $(HOSTNM) || echo nm)

ifndef CFLAGS_FOR_BUILD

CFLAGS_FOR_BUILD:=-g -O2

endif