Enabled C backend for structs_03

Author: czgdp1807

.gitignore

@@ -181,3 +181,5 @@ integration_tests/structs_01
 integration_tests/structs_01.c
 integration_tests/structs_02
 integration_tests/structs_02.c
+integration_tests/structs_03
+integration_tests/structs_03.c

integration_tests/CMakeLists.txt

@@ -171,7 +171,7 @@ RUN(NAME test_bool_binop     LABELS cpython llvm)
 RUN(NAME test_issue_518      LABELS cpython llvm)
 RUN(NAME structs_01          LABELS cpython llvm c)
 RUN(NAME structs_02          LABELS llvm c)
-RUN(NAME structs_03          LABELS llvm)
+RUN(NAME structs_03          LABELS llvm c)
 
 # Just CPython
 RUN(NAME test_builtin_bin    LABELS cpython)