[coreml] Use special throw macro when encountering CoreML API errors (#77429)

Summary: Error messages from `TORCH_CHECK` are stripped during production builds via  `-DSTRIP_ERROR_MESSAGES`. This diff introduces a new macro `COREML_CHECK` which will always preserve the error message. This macro is used when encountering errors produced by CoreML API calls so that we can heve enough context to debug.

Test Plan:
Test in pytorch playground:

```
arc focus2 -b pp-ios -a ModelRunner -a //xplat/caffe2/c10:c10Apple -a //xplat/caffe2:torch_mobile_coreApple  -a //xplat/caffe2/fb/dynamic_pytorch:dynamic_pytorch_implApple -a //xplat/caffe2:coreml_delegateApple  -a ModelRunnerDevOps -a //xplat/caffe2:torch_mobile_all_opsApple -fd --force-with-wrong-xcode
```

Differential Revision: D36378286

Pull Request resolved: https://github.com/pytorch/pytorch/pull/77429
Approved by: https://github.com/kimishpatel

torch/csrc/jit/backends/coreml/objc/PTMCoreMLExecutor.mm

@@ -14,6 +14,24 @@
 #include <fstream>
 #include <iostream>
 
+// This is a utility macro that can be used to throw an exception when a CoreML
+// API function produces a NSError. The exception will contain a message with
+// useful info extracted from the NSError.
+#define COREML_THROW_IF_ERROR(error, preamble)                                   \
+  do {                                                                           \
+    if C10_LIKELY(error) {                                                       \
+      throw c10::Error(                                                          \
+          {__func__, __FILE__, static_cast<uint32_t>(__LINE__)},                 \
+          c10::str(                                                              \
+              preamble,                                                          \
+              " Error details: ",                                                \
+              " Localized_description: ", error.localizedDescription.UTF8String, \
+              " Domain: ", error.domain.UTF8String,                              \
+              " Code: ", error.code,                                             \
+              " User Info: ", error.userInfo.description.UTF8String));           \
+    }                                                                            \
+  } while (false)
+
 @implementation PTMCoreMLFeatureProvider {
   NSUInteger _coremlVersion;
   std::vector<PTMCoreMLFeatureSpecs> _specs;
@@ -173,10 +191,8 @@ static NSString* gModelCacheDirectory = @"";
 
     // remove cached models if compalition failed.
     [self cleanup];
-    TORCH_CHECK(
-        false,
-        "Error compiling the MLModel",
-        [error localizedDescription].UTF8String);
+
+    COREML_THROW_IF_ERROR(error, "Error compiling the MLModel file!");
     return NO;
   }
   if (@available(iOS 12.0, macOS 10.14, *)) {
@@ -201,10 +217,7 @@ static NSString* gModelCacheDirectory = @"";
       observer->onExitCompileModel(instance_key, false, true);
     }
 
-    TORCH_CHECK(
-        false,
-        "Error loading the MLModel",
-        error.localizedDescription.UTF8String);
+    COREML_THROW_IF_ERROR(error, "Error loading the MLModel file!");
   }
 
   if (observer) {
@@ -240,12 +253,8 @@ static NSString* gModelCacheDirectory = @"";
           [_mlModel predictionFromFeatures:inputFeature
                                    options:options
                                      error:&error];
-      if (error) {
-        TORCH_CHECK(
-            false,
-            "Error running the prediction",
-            error.localizedDescription.UTF8String);
-      }
+
+      COREML_THROW_IF_ERROR(error, "Error running CoreML inference!");
 
       ++_inferences;
       if (observer) {