Added test based on basic_new_heap function

Author: anutosh491

integration_tests/CMakeLists.txt

@@ -624,6 +624,7 @@ RUN(NAME symbolics_03        LABELS cpython_sym c_sym)
 RUN(NAME symbolics_04        LABELS cpython_sym c_sym)
 RUN(NAME symbolics_05        LABELS cpython_sym c_sym)
 RUN(NAME symbolics_06        LABELS cpython_sym c_sym)
+RUN(NAME symbolics_07        LABELS cpython_sym c_sym)
 
 RUN(NAME sizeof_01           LABELS llvm c
         EXTRAFILES sizeof_01b.c)

integration_tests/symbolics_07.py

@@ -0,0 +1,22 @@
+from lpython import ccall
+
+@ccall(header="symengine/cwrapper.h")
+def basic_new_heap() -> CPtr:
+    pass
+
+@ccall(header="symengine/cwrapper.h")
+def basic_const_pi(x: CPtr) -> None:
+    pass
+
+@ccall(header="symengine/cwrapper.h")
+def basic_str(x: CPtr) -> str:
+    pass
+
+def main0():
+    x: CPtr = basic_new_heap()
+    basic_const_pi(x)
+    s: str = basic_str(x)
+    print(s)
+    assert s == "pi"
+
+main0()