Try and fix build on mac.

gpt4all-backend/llmodel_shared.cpp

@@ -0,0 +1,26 @@
+#include "llmodel.h"
+
+#include <cassert>
+#include <iostream>
+
+void LLModel::recalculateContext(PromptContext &promptCtx, std::function<bool(bool)> recalculate) {
+    size_t i = 0;
+    promptCtx.n_past = 0;
+    while (i < promptCtx.tokens.size()) {
+        size_t batch_end = std::min(i + promptCtx.n_batch, promptCtx.tokens.size());
+        std::vector<int32_t> batch(promptCtx.tokens.begin() + i, promptCtx.tokens.begin() + batch_end);
+        assert(promptCtx.n_past + int32_t(batch.size()) <= promptCtx.n_ctx);
+        if (!evalTokens(promptCtx, batch)) {
+            std::cerr << "LLModel ERROR: Failed to process prompt\n";
+            goto stop_generating;
+        }
+        promptCtx.n_past += batch.size();
+        if (!recalculate(true))
+            goto stop_generating;
+        i = batch_end;
+    }
+    assert(promptCtx.n_past == int32_t(promptCtx.tokens.size()));
+
+stop_generating:
+    recalculate(false);
+}