Include C++ header in native nuget and fix compiler warnings (#1727)

This pull request enhances the native NuGet package by including both
the C and C++ header files. Previously, only the C header was bundled.
With this update, the package now supports both languages more
comprehensively.

Additionally, this PR resolves several compiler warnings that stemmed
from unchecked return values in calls to the ONNX Runtime API.

Author: baijumeswani

src/models/onnxruntime_api.h

@@ -425,13 +425,9 @@ std::span<TAlloc> Allocate(OrtAllocator& allocator,
   return std::span(unique_ptr.get(), size);
 }
 
-inline void RegisterExecutionProviderLibrary(OrtEnv* env, const char* registration_name, const ORTCHAR_T* path) {
-  Ort::api->RegisterExecutionProviderLibrary(env, registration_name, path);
-}
+void RegisterExecutionProviderLibrary(OrtEnv* env, const char* registration_name, const ORTCHAR_T* path);
 
-inline void UnregisterExecutionProviderLibrary(OrtEnv* env, const char* registration_name) {
-  Ort::api->UnregisterExecutionProviderLibrary(env, registration_name);
-}
+void UnregisterExecutionProviderLibrary(OrtEnv* env, const char* registration_name);
 
 }  // namespace Ort
 

src/models/onnxruntime_inline.h

@@ -185,6 +185,14 @@ inline int GetCurrentGpuDeviceId() {
   return id;
 }
 
+inline void RegisterExecutionProviderLibrary(OrtEnv* env, const char* registration_name, const ORTCHAR_T* path) {
+  ThrowOnError(Ort::api->RegisterExecutionProviderLibrary(env, registration_name, path));
+}
+
+inline void UnregisterExecutionProviderLibrary(OrtEnv* env, const char* registration_name) {
+  ThrowOnError(Ort::api->UnregisterExecutionProviderLibrary(env, registration_name));
+}
+
 }  // namespace Ort
 
 inline std::unique_ptr<OrtStatus> OrtStatus::Create(OrtErrorCode code, const std::string& what) {

tools/nuget/generate_nuspec_for_native_nuget.py

@@ -155,6 +155,7 @@ def add_native_artifact_if_exists(xml_lines, runtime, artifact):
 
     # include
     lines.append(f'<file src="{args.sources_path}\src\ort_genai_c.h" target="build\\native\include" />')
+    lines.append(f'<file src="{args.sources_path}\src\ort_genai.h" target="build\\native\include" />')
     lines.append('</files>')