Port to ICU LayoutEngine C API

Incidentally, this makes it not crash with icu-le-hb anymore...
I'm not smart / stupid enough to spend two more days debugging C++
linking issues, and this is ABI-stable at least.

src/hb-icu-le.cc

@@ -30,7 +30,7 @@
 
 #include "hb-icu-le/PortableFontInstance.h"
 
-#include "layout/LayoutEngine.h"
+#include "layout/loengine.h"
 #include "unicode/unistr.h"
 
 #include "hb-icu.h"
@@ -117,13 +117,13 @@ _hb_icu_le_shape (hb_shape_plan_t    *shape_plan,
   le_int32 language_code = -1 /* TODO */;
   le_int32 typography_flags = 3; // essential for ligatures and kerning
   LEErrorCode status = LE_NO_ERROR;
-  LayoutEngine *le = LayoutEngine::layoutEngineFactory (font_instance,
+  le_engine *le = le_create ((const le_font *) font_instance,
 			     script_code,
 			     language_code,
 			     typography_flags,
-							status);
+			     &status);
   if (status != LE_NO_ERROR)
-  { delete (le); return false; }
+  { le_close (le); return false; }
 
 retry:
 
@@ -143,15 +143,16 @@ retry:
     clusters[i] = buffer->info[i].cluster;
   }
 
-  unsigned int glyph_count = le->layoutChars(chars,
+  unsigned int glyph_count = le_layoutChars (le,
+					     chars,
 					     0,
 					     buffer->len,
 					     buffer->len,
 					     HB_DIRECTION_IS_BACKWARD (buffer->props.direction),
 					     0., 0.,
-					     status);
+					     &status);
   if (status != LE_NO_ERROR)
-  { delete (le); return false; }
+  { le_close (le); return false; }
 
   unsigned int num_glyphs = scratch_size / (sizeof (LEGlyphID) +
 					    sizeof (le_int32) +
@@ -160,7 +161,7 @@ retry:
   if (unlikely (glyph_count >= num_glyphs || glyph_count > buffer->allocated)) {
     buffer->ensure (buffer->allocated * 2);
     if (buffer->in_error)
-    { delete (le); return false; }
+    { le_close (le); return false; }
     goto retry;
   }
 
@@ -168,9 +169,9 @@ retry:
   ALLOCATE_ARRAY (le_int32, indices, glyph_count);
   ALLOCATE_ARRAY (float, positions, glyph_count * 2 + 2);
 
-  le->getGlyphs(glyphs, status);
-  le->getCharIndices(indices, status);
-  le->getGlyphPositions(positions, status);
+  le_getGlyphs (le, glyphs, &status);
+  le_getCharIndices (le, indices, &status);
+  le_getGlyphPositions (le, positions, &status);
 
 #undef ALLOCATE_ARRAY
 
@@ -208,6 +209,6 @@ retry:
     pos->y_offset = info->var2.u32;
   }
 
-  delete (le);
+  le_close (le);
   return true;
 }