Marking CORE more Shadow Memory regression tests

Marking as CORE all the shadow memory regression tests that are now
passing.

The remaining regression tests that are still marked as KNOWNBUG will be
added as soon as the implementation will be fixed.

Author: NlightNFotis

regression/cbmc-shadow-memory/char1/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+CORE
 main.c
 
 ^EXIT=0$

regression/cbmc-shadow-memory/constchar-pointers1/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+CORE
 main.c
 --unwind 11
 ^EXIT=0$

regression/cbmc-shadow-memory/linked-list1/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+CORE
 main.c
 
 ^EXIT=0$

regression/cbmc-shadow-memory/linked-list2/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+CORE
 main.c
 
 ^EXIT=0$

regression/cbmc-shadow-memory/maybe-null1/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+CORE
 main.c
 
 ^EXIT=0$

regression/cbmc-shadow-memory/nondet-size-arrays1/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+CORE
 main.c
 
 ^EXIT=0$

regression/cbmc-shadow-memory/struct-set1/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+CORE
 main.c
 
 ^EXIT=0$

regression/cbmc-shadow-memory/taint-example1/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+CORE
 main.c
 --unwind 15
 ^EXIT=0$

regression/cbmc-shadow-memory/union-get-max1/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+CORE
 main.c
 
 ^EXIT=0$

regression/cbmc-shadow-memory/union-get-or1/test.desc

@@ -1,4 +1,4 @@
-KNOWNBUG
+CORE
 main.c
 
 ^EXIT=0$