force cross compiler/cross compiling

now that config.guess knows how to detect musl, it's possible when
building on a musl-based system that $build will spuriously match
$target, preventing the desired behavior of building as a cross
compiler or as a cross-compiled native compiler.

run config.guess and config.sub from the litecross makefile to check
if $build is going to match $target, and if so, append junk to the
libc/abi part of the $build tuple so that it no longer matches.

litecross/Makefile

@@ -86,8 +86,15 @@ ifneq ($(NATIVE),)
 HOST:=$(TARGET)
 endif
 
+ifeq ($(BUILD),)
+GUESS = $(shell cd $(GCC_SRCDIR) && ./config.guess)
+TARGET_CANON = $(shell cd $(GCC_SRCDIR) && ./config.sub $(TARGET))
+BUILD = $(GUESS)$(if $(subst $(TARGET_CANON),,$(GUESS)),,xx)
+endif
+
 ifeq ($(HOST),)
 SYSROOT = /$(TARGET)
+FULL_BINUTILS_CONFIG += --build=$(BUILD) --host=$(BUILD)
 FULL_GCC_CONFIG += --with-build-sysroot=$(CURDIR)/obj_sysroot \
 	AR_FOR_TARGET=$(PWD)/obj_binutils/binutils/ar \
 	AS_FOR_TARGET=$(PWD)/obj_binutils/gas/as-new \
@@ -98,6 +105,7 @@ FULL_GCC_CONFIG += --with-build-sysroot=$(CURDIR)/obj_sysroot \
 	RANLIB_FOR_TARGET=$(PWD)/obj_binutils/binutils/ranlib \
 	READELF_FOR_TARGET=$(PWD)/obj_binutils/binutils/readelf \
 	STRIP_FOR_TARGET=$(PWD)/obj_binutils/binutils/strip-new \
+	--build=$(BUILD) --host=$(BUILD) \
 	# end
 FULL_MUSL_CONFIG += CC="$(XGCC)" LIBCC="../obj_gcc/$(TARGET)/libgcc/libgcc.a" 
 MUSL_VARS = AR=../obj_binutils/binutils/ar RANLIB=../obj_binutils/binutils/ranlib
@@ -108,8 +116,8 @@ obj_gcc/.lc_built: | obj_sysroot/.lc_libs obj_sysroot/.lc_headers
 obj_gcc/.lc_configured: obj_binutils/.lc_built
 else
 SYSROOT = /
-FULL_BINUTILS_CONFIG += --host=$(HOST)
-FULL_GCC_CONFIG += --host=$(HOST)
+FULL_BINUTILS_CONFIG += --build=$(BUILD) --host=$(HOST)
+FULL_GCC_CONFIG += --build=$(BUILD) --host=$(HOST)
 MUSL_VARS = 
 endif