Re-add pointer dec tests

src/example-archive/c-testsuite/broken/error-proof/00073.err1.c

@@ -0,0 +1,20 @@
+/*
+cn: internal error, uncaught exception:
+    Failure("todo")
+*/
+// Cause: `-=` assignment operator 
+
+int
+main()
+{
+	int arr[2];
+	int *p;
+
+	p = &arr[1];
+	p -= 1;
+	*p = 123;
+
+	if(arr[0] != 123)
+		return 1;
+	return 0;
+}

src/example-archive/c-testsuite/working/00032.c

@@ -0,0 +1,35 @@
+// Crash: caused by pointer decrement 
+
+int
+main()
+/*@ ensures return == 0i32; @*/
+{
+	int arr[2];
+	int *p;
+
+	/*@ extract Block<int>, 0u64; @*/
+	arr[0] = 2;
+	/*@ extract Block<int>, 1u64; @*/
+	arr[1] = 3;
+	p = &arr[0];
+	if(*(p++) != 2)
+		return 1;
+	if(*(p++) != 3)
+		return 2;
+
+	p = &arr[1];
+	if(*(p--) != 3)
+		return 1;
+	if(*(p--) != 2)
+		return 2;
+
+	p = &arr[0];
+	if(*(++p) != 3)
+		return 1;
+
+	p = &arr[1];
+	if(*(--p) != 2) // <-- cause of the crash  
+		return 1;
+
+	return 0;
+}

src/example-archive/simple-examples/broken/error-proof/pointer_dec3.c

@@ -0,0 +1,9 @@
+// Crash 
+
+void
+pointerdec_crash_3()
+{
+  int arr[2];
+  int *p = &arr[1];
+  *(--p); 
+}

src/example-archive/simple-examples/working/pointer_dec1.c

@@ -0,0 +1,5 @@
+int a;
+void b() {
+  int *c = &a;
+  c -= 1;
+}

src/example-archive/simple-examples/working/pointer_dec2.c

@@ -0,0 +1,7 @@
+// Derived from src/example-archive/c-testsuite/broken/error-proof/00032.err1.c
+
+int a;
+void b() {
+  int *c = &a;
+  --c;
+}