Updated reference tests

Author: czgdp1807

.gitignore

@@ -168,4 +168,5 @@ src/lpython/parser/parser.tab.hh
 integration_tests/test_c_interop_01.c
 integration_tests/test_c_interop_01
 integration_tests/test_c_interop_03
+integration_tests/test_c_interop_03.c
 integration_tests/test_c_interop_04

integration_tests/CMakeLists.txt

@@ -154,7 +154,7 @@ RUN(NAME test_math_02        LABELS cpython llvm)
 RUN(NAME test_c_interop_01   LABELS cpython llvm c)
 RUN(NAME test_c_interop_02   LABELS cpython llvm c
         EXTRAFILES test_c_interop_02b.c)
-RUN(NAME test_c_interop_03   LABELS llvm
+RUN(NAME test_c_interop_03   LABELS llvm c
         EXTRAFILES test_c_interop_03b.c)
 RUN(NAME test_c_interop_04   LABELS llvm
         EXTRAFILES test_c_interop_04b.c)