Switch on tests fixed by adding empty struct encoding

Author: thomasspriggs

regression/cbmc/Empty_struct1/test.desc

@@ -1,4 +1,4 @@
-CORE gcc-only
+CORE gcc-only new-smt-backend
 main.c
 
 ^EXIT=0$

regression/cbmc/Empty_struct2/test.desc

@@ -1,4 +1,4 @@
-CORE gcc-only
+CORE gcc-only new-smt-backend
 main.c
 
 ^EXIT=0$

regression/cbmc/empty_compound_type1/test.desc

@@ -1,4 +1,4 @@
-CORE gcc-only
+CORE gcc-only new-smt-backend
 main.c
 
 ^EXIT=0$

regression/cbmc/empty_compound_type2/test.desc

@@ -1,4 +1,4 @@
-CORE gcc-only
+CORE gcc-only new-smt-backend
 main.c
 --pointer-check
 ^EXIT=10$

regression/cbmc/empty_compound_type3/test.desc

@@ -1,4 +1,4 @@
-CORE gcc-only
+CORE gcc-only new-smt-backend
 main.c
 
 ^EXIT=10$