[HIP] Correct headers and add missing function templates for hip-clang.

- Fix 2 runtime API prototypes
  `hipOccupancyMaxActiveBlocksPerMultiprocessor` and
  `hipOccupancyMaxActiveBlocksPerMultiprocessorWithFlags`
- Add missing function templates of them in hip-clang.

include/hip/hcc_detail/hip_runtime_api.h

@@ -3219,6 +3219,21 @@ hipError_t hipLaunchKernel(const void* function_address,
 } /* extern "c" */
 #endif
 
+#if defined(__cplusplus) && !defined(__HCC__) && defined(__clang__) && defined(__HIP__)
+template <typename F>
+static hipError_t __host__ inline hipOccupancyMaxActiveBlocksPerMultiprocessor(
+    uint32_t* numBlocks, F func, uint32_t blockSize, size_t dynSharedMemPerBlk) {
+    return ::hipOccupancyMaxActiveBlocksPerMultiprocessor(numBlocks, (hipFunction_t)func, blockSize,
+                                                          dynSharedMemPerBlk);
+}
+template <typename F>
+static hipError_t __host__ inline hipOccupancyMaxActiveBlocksPerMultiprocessorWithFlags(
+    uint32_t* numBlocks, F func, uint32_t blockSize, size_t dynSharedMemPerBlk, unsigned int flags) {
+    return ::hipOccupancyMaxActiveBlocksPerMultiprocessorWithFlags(
+        numBlocks, (hipFunction_t)func, blockSize, dynSharedMemPerBlk, flags);
+}
+#endif  // defined(__cplusplus) && !defined(__HCC__) && defined(__clang__) && defined(__HIP__)
+
 #if USE_PROF_API
 #include <hip/hcc_detail/hip_prof_str.h>
 #endif