Update min-unwind tests for behaviour of different unwind values

It is agreed that if --unwind N can find an error, that unwind-min N
should find the same error. That is, we start checking immediately after
doing N unwinds, rather than after doing N increments of the incremental
unwinding (i.e. unwind + solve)

Author: Thomas Kiley

regression/cbmc-incr-oneloop/ignore-before-unwind/include_first_unwind0.desc

@@ -0,0 +1,12 @@
+CORE
+main.c
+--ignore-properties-before-unwind-min --incremental-loop main.0 --unwind-max 2 --unwind-min 0
+^EXIT=10$
+^SIGNAL=0$
+^\[main.assertion.\d+\] line \d+ property: FAILURE$
+^VERIFICATION FAILED$
+--
+^warning: ignoring
+--
+This test correctly fails because the first iteration of the loop violates the
+property.

regression/cbmc-incr-oneloop/ignore-before-unwind/include_first_unwind1.desc

@@ -0,0 +1,12 @@
+CORE
+main.c
+--ignore-properties-before-unwind-min --incremental-loop main.0 --unwind-max 2 --unwind-min 1
+^EXIT=10$
+^SIGNAL=0$
+^\[main.assertion.\d+\] line \d+ property: FAILURE$
+^VERIFICATION FAILED$
+--
+^warning: ignoring
+--
+This test correctly fails because the first iteration of the loop violates the
+property.

regression/cbmc-incr-oneloop/ignore-before-unwind/skip_first_unwind.desc

@@ -1,6 +1,6 @@
 CORE
 main.c
---ignore-properties-before-unwind-min --incremental-loop main.0 --unwind-max 2 --unwind-min 1
+--ignore-properties-before-unwind-min --incremental-loop main.0 --unwind-max 2 --unwind-min 2
 ^EXIT=0$
 ^SIGNAL=0$
 ^VERIFICATION SUCCESSFUL$