test(bpu): add two simple bpu test to src/test/testcase

src/test/testcase/Makefile

+include $(AM_HOME)/Makefile.check
+.PHONY: all run clean latest $(ALL)
+
+ALL = $(basename $(notdir $(shell find tests/. -name "*.c")))
+
+all: $(addprefix Makefile., $(ALL))
+	@echo "" $(ALL)
+
+$(ALL): %: Makefile.%
+
+Makefile.%: tests/%.c latest
+	@/bin/echo -e "NAME = $*\nSRCS = $<\nLIBS += klib\ninclude $${AM_HOME}/Makefile.app" > $@
+	-@make -s -f $@ ARCH=$(ARCH) $(MAKECMDGOALS)
+	-@rm -f Makefile.$*
+
+#cancel rules included by $(AM_HOME)/Makefile.check
+image: ;
+default $(MAKECMDGOALS): all ;
+
+clean:
+	rm -rf Makefile.* build/
+
+latest:
\ No newline at end of file

src/test/testcase/tests/double-loop.c

+// #include <am.h>
+// #include <klib.h>
+
+# define OutLoopNum 20
+# define InnerLoopNum 20
+
+int array[OutLoopNum][InnerLoopNum];
+
+void double_loop() {
+    for (int i = 0; i < OutLoopNum; i++) {
+        for (int j = 1; j < InnerLoopNum; j++) {
+            array[i][j] = i + j;
+        }
+    }
+}
+
+int main () {
+    double_loop();
+    return 0;
+}

src/test/testcase/tests/nested-loop.c

+// #include <am.h>
+// #include <klib.h>
+
+# define DEPTH 100
+
+int nest(int depth) {
+    if (depth == 0) return depth;
+    nest(depth - 1);
+    return depth;
+}
+
+int main () {
+    nest(DEPTH);
+    return 0;
+}