Use Apple's PUA Unicode data

oops

stdlib/public/stubs/Unicode/UnicodeGrapheme.cpp

@@ -0,0 +1,59 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2021 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "Common/GraphemeData.h"
+#include "../SwiftShims/UnicodeData.h"
+
+SWIFT_RUNTIME_STDLIB_INTERNAL
+__swift_uint8_t _swift_stdlib_getGraphemeBreakProperty(__swift_uint32_t scalar) {
+  auto low = 0;
+  auto high = GRAPHEME_BREAK_DATA_COUNT - 1;
+
+  while (high >= low) {
+    auto idx = low + (high - low) / 2;
+
+    auto entry = _swift_stdlib_graphemeBreakProperties[idx];
+
+    // Shift the enum and range count out of the value.
+    auto lower = (entry << 11) >> 11;
+
+    // Shift the enum out first, then shift out the scalar value.
+    auto upper = lower + ((entry << 3) >> 24);
+
+    // Shift everything out.
+    auto enumValue = (__swift_uint8_t)(entry >> 29);
+
+    // Special case: extendedPictographic who used an extra bit for the range.
+    if (enumValue == 5) {
+      upper = lower + ((entry << 2) >> 23);
+    }
+
+    if (scalar >= lower && scalar <= upper) {
+      return enumValue;
+    }
+
+    if (scalar > upper) {
+      low = idx + 1;
+      continue;
+    }
+
+    if (scalar < lower) {
+      high = idx - 1;
+      continue;
+    }
+  }
+
+  // If we made it out here, then our scalar was not found in the grapheme
+  // array (this occurs when a scalar doesn't map to any grapheme break
+  // property). Return the max value here to indicate .any.
+  return 0xFF;
+}