[AIX]Blocking the call of dladdr under _AIX (#26513)

### Description
In AIX, dladdr() is not supported so blocking the call of dladdr API
under _AIX.
we don't have support of cpuinfo pkg also which generates a warning at
runtime.

This PR is to fox the issues mentioned above.


### Motivation and Context

1. Fix for below compilation error
```
/home/buildusr/jenkins/workspace/onnxruntime-openxl/onnxruntime/onnxruntime/core/platform/posix/env.cc:562:9: error: unknown type name 'Dl_info'
  562 |     if (Dl_info dl_info{};
```

2. Fix for below warning during test application executions.

`2025-11-06 07:23:44.176700000 [W:onnxruntime:Default, cpuid_info.cc:95
LogEarlyWarning] Unknown CPU vendor. cpuinfo_vendor value: 0`

Author: ranjitshs

cmake/onnxruntime_unittests.cmake

@@ -1528,8 +1528,14 @@ endif()
       onnxruntime_add_shared_library(onnxruntime_runtime_path_test_shared_library
                                      ${onnxruntime_runtime_path_test_shared_library_src})
 
-      target_link_libraries(onnxruntime_runtime_path_test_shared_library PRIVATE
-                            onnxruntime_common cpuinfo ${CMAKE_DL_LIBS})
+      if (CMAKE_SYSTEM_NAME MATCHES "AIX")
+        target_link_libraries(onnxruntime_runtime_path_test_shared_library PRIVATE
+                              onnxruntime_common ${CMAKE_DL_LIBS})
+        set_target_properties(onnxruntime_runtime_path_test_shared_library PROPERTIES AIX_SHARED_LIBRARY_ARCHIVE OFF)
+      else()
+        target_link_libraries(onnxruntime_runtime_path_test_shared_library PRIVATE
+                              onnxruntime_common cpuinfo ${CMAKE_DL_LIBS})
+      endif()
       target_include_directories(onnxruntime_runtime_path_test_shared_library PRIVATE ${ONNXRUNTIME_ROOT})
 
       if(UNIX)

onnxruntime/core/common/cpuid_info_vendor.cc

@@ -198,7 +198,7 @@ constexpr std::array kCpuVendorInfos{
     CpuVendorInfo{cpuinfo_vendor_nvidia, "Nvidia", 0x10DE},
     CpuVendorInfo{cpuinfo_vendor_apple, "Apple", 0x106B},
     CpuVendorInfo{cpuinfo_vendor_arm, "ARM", 0x13B5},
-
+    CpuVendorInfo{cpuinfo_vendor_ibm, "IBM", 0x1014},
     // TODO add more as needed
 };
 
@@ -228,6 +228,9 @@ void CPUIDInfo::VendorInfoInit() {
       }
     }
 #endif  // defined(CPUINFO_SUPPORTED)
+#if defined(_AIX)
+    result = cpuinfo_vendor_ibm;
+#endif
     return result;
   }();
 

onnxruntime/core/platform/posix/env.cc

@@ -556,6 +556,8 @@ class PosixEnv : public Env {
   }
 
   PathString GetRuntimePath() const override {
+// In AIX, dladdr is not supported.
+#if !defined(_AIX)
     // Use dladdr() to look up the file that contains an address from this binary.
     const void* const address_from_this_binary = reinterpret_cast<const void*>(Env::Default);
 
@@ -568,7 +570,7 @@ class PosixEnv : public Env {
       runtime_path.remove_filename();
       return runtime_path;
     }
-
+#endif
     return PathString{};
   }
 

onnxruntime/test/shared_lib/test_runtime_path.cc

@@ -21,7 +21,11 @@ bool IsDirectorySeparator(PathChar c) {
 }
 }  // namespace
 
+#if !defined(_AIX)
 TEST(GetRuntimePathFromSharedLibraryTest, Basic) {
+#else
+TEST(GetRuntimePathFromSharedLibraryTest, DISABLED_Basic) {
+#endif
   const auto* runtime_path_cstr = OrtTestGetSharedLibraryRuntimePath();
   ASSERT_NE(runtime_path_cstr, nullptr);