whisper : add Core ML support (#566)

* coreml : use Core ML encoder inference

* coreml : simlpify whisper_encode + log messages

* whisper : resolve rebase conflicts

* coreml : add scripts for CoreML model generation

* bench-all : recognize COREML flag

models/generate-coreml-model.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+
+# Usage: ./generate-coreml-model.sh <model-name>
+if [ $# -eq 0 ]
+  then
+    echo "No model name supplied"
+    echo "Usage: ./generate-coreml-model.sh <model-name>"
+    exit 1
+fi
+
+mname="$1"
+
+wd=$(dirname "$0")
+cd "$wd/../"
+
+python3 models/convert-whisper-to-coreml.py --model $mname --encoder-only True
+
+xcrun coremlc compile models/coreml-encoder-${mname}.mlpackage models/
+rm -rf models/ggml-${mname}-encoder.mlmodelc
+mv -v models/coreml-encoder-${mname}.mlmodelc models/ggml-${mname}-encoder.mlmodelc
+
+# TODO: decoder (sometime in the future maybe)
+#xcrun coremlc compile models/whisper-decoder-${mname}.mlpackage models/
+#rm -rf models/ggml-${mname}-decoder.mlmodelc
+#mv -v models/coreml_decoder_${mname}.mlmodelc models/ggml-${mname}-decoder.mlmodelc