Fixed SM failing regressions tests.

Fixed SM failing regression tests due to better error messaging on
typecheck.

Author: Enrico Steffinlongo

regression/cbmc-shadow-memory/declarations1/test_bad1.desc

@@ -3,7 +3,8 @@ bad1.c
 --function bad_declaration1 --verbosity 10
 ^EXIT=6$
 ^SIGNAL=0$
-^A shadow memory field must not be larger than 8 bits.
+^file bad1\.c line 3 function bad_declaration1: __CPROVER_field_decl_local argument 2 must be a byte-sized integer, but \(\(signed int\)0\) has type `signed int`
+^CONVERSION ERROR
 --
 --
 Test that a shadow memory declaration of a too large type is rejected.

regression/cbmc-shadow-memory/declarations1/test_bad2.desc

@@ -3,7 +3,8 @@ bad2.c
 --function bad_declaration2 --verbosity 10
 ^EXIT=6$
 ^SIGNAL=0$
-^A shadow memory field must be of a bitvector type.
+^file bad2\.c line 7 function bad_declaration2: __CPROVER_field_decl_global argument 2 must be a byte-sized integer, but \(s\) has type `struct STRUCT`
+^CONVERSION ERROR
 --
 --
 Test that a shadow memory declaration of a non-bitvector type is rejected.

regression/cbmc-shadow-memory/void-ptr-param-get1/test.desc

@@ -3,6 +3,7 @@ main.c
 
 ^EXIT=6$
 ^SIGNAL=0$
-Shadow memory: cannot get shadow memory via type void\* for f_void_ptr::s
+^file main\.c line 12 function f_void_ptr: __CPROVER_get_field argument 1 must be a non-void pointer, but \(s\) has type `void \*`. Insert a cast to the type that you want to access\.
+CONVERSION ERROR
 --
 ^warning: ignoring

regression/cbmc-shadow-memory/void-ptr-param-set1/test.desc

@@ -3,6 +3,7 @@ main.c
 
 ^EXIT=6$
 ^SIGNAL=0$
-Shadow memory: cannot set shadow memory via type void\* for f_void_ptr::s
+^file main\.c line 12 function f_void_ptr: __CPROVER_set_field argument 1 must be a non-void pointer, but \(s\) has type `void \*`\. Insert a cast to the type that you want to access\.
+^CONVERSION ERROR
 --
 ^warning: ignoring