Makes the DynMemRef.h usable from C (#101)

src/Runtime/DynMemRef.h

@@ -1,6 +1,10 @@
+#ifdef __cplusplus
 #pragma once
 
 #include <cstdint>
+#else
+#include <stdint.h>
+#endif
 
 typedef int64_t INDEX_TYPE;
 
@@ -16,15 +20,26 @@ struct DynMemRef {
   INDEX_TYPE *sizes;
   int64_t *strides;
 
+#ifdef __cplusplus
   DynMemRef(int _rank);
+#endif
 };
 
-extern "C" {
-
+#ifdef __cplusplus
 // Ordered DynMemRef Dictionary is a data structure for wrapping the input
 // dynmemrefs so that they can be addressed both by index and by name.
 struct OrderedDynMemRefDict;
 
+#else
+typedef struct DynMemRef DynMemRef;
+typedef struct _OrderedDynMemRefDict OrderedDynMemRefDict;
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+  
+
 // Get number of dynamic memrefs in OrderedDynMemRefDict dict.
 int numDynMemRefs(OrderedDynMemRefDict *dict);
 
@@ -58,4 +73,7 @@ INDEX_TYPE *getSizes(DynMemRef *);
 
 // Get ptr to strides array.
 int64_t *getStrides(DynMemRef *);
+
+#ifdef __cplusplus
 }
+#endif