Round, instead of floor, when applying variations

Hoping this would fix remaining text-rendering-tests failures,
but so far no luck.

src/hb-font-private.hh

@@ -541,7 +541,7 @@ struct hb_font_t {
   }
   inline hb_position_t em_scalef (float v, int scale)
   {
-    return (hb_position_t) (v * scale / face->get_upem ());
+    return (hb_position_t) round (v * scale / face->get_upem ());
   }
 };
 

src/hb-ot-layout-gpos-table.hh

@@ -333,7 +333,7 @@ struct Anchor
     case 1: u.format1.get_anchor (c, glyph_id, x, y); return;
     case 2: u.format2.get_anchor (c, glyph_id, x, y); return;
     case 3: u.format3.get_anchor (c, glyph_id, x, y); return;
-    default:						 return;
+    default:					      return;
     }
   }
 

src/hb-private.hh

@@ -40,6 +40,7 @@
 #define HB_OT_H_IN
 #endif
 
+#include <math.h>
 #include <stdlib.h>
 #include <stddef.h>
 #include <string.h>