add simple overflow tests

test/simple-memory-corruption/Makefile

@@ -18,6 +18,8 @@ EXECUTABLES := \
     uninitialized_free \
     uninitialized_realloc \
     uninitialized_malloc_usable_size \
+    eight_byte_overflow_small \
+    eight_byte_overflow_large \
 
 all: $(EXECUTABLES)
 

test/simple-memory-corruption/eight_byte_overflow_large.c

@@ -0,0 +1,12 @@
+#include <stdlib.h>
+
+__attribute__((optimize(0)))
+int main(void) {
+    char *p = malloc(128 * 1024);
+    if (!p) {
+        return 1;
+    }
+    *(p + 128 * 1024 + 7) = 0;
+    free(p);
+    return 0;
+}

test/simple-memory-corruption/eight_byte_overflow_small.c

@@ -0,0 +1,12 @@
+#include <stdlib.h>
+
+__attribute__((optimize(0)))
+int main(void) {
+    char *p = malloc(8);
+    if (!p) {
+        return 1;
+    }
+    *(p + 8 + 7) = 0;
+    free(p);
+    return 0;
+}