give us a parenStack which can grow to fit any input

Change-Id: Ic464184fe367da33bf8c4790b82656b140e3cbd0

vcl/generic/glyphs/scrptrun.cxx

@@ -175,7 +175,11 @@ UBool ScriptRun::next()
         // characters above it on the stack will be poped.
         if (pairIndex >= 0) {
             if ((pairIndex & 1) == 0) {
-                parenStack[++parenSP].pairIndex = pairIndex;
+                ++parenSP;
+                int32_t nVecSize = parenStack.size();
+                if (parenSP == nVecSize)
+                    parenStack.resize(nVecSize + 128);
+                parenStack[parenSP].pairIndex = pairIndex;
                 parenStack[parenSP].scriptCode  = scriptCode;
             } else if (parenSP >= 0) {
                 int32_t pi = pairIndex & ~1;

vcl/generic/glyphs/scrptrun.h

@@ -43,6 +43,7 @@
 #include "unicode/utypes.h"
 #include "unicode/uobject.h"
 #include "unicode/uscript.h"
+#include <vector>
 
 namespace vcl {
 
@@ -112,7 +113,7 @@ private:
     int32_t scriptEnd;
     UScriptCode scriptCode;
 
-    ParenStackEntry parenStack[128];
+    std::vector<ParenStackEntry> parenStack;
     int32_t parenSP;
 
     static int8_t highBit(int32_t value);
@@ -166,6 +167,7 @@ inline void ScriptRun::reset()
     scriptEnd   = charStart;
     scriptCode  = USCRIPT_INVALID_CODE;
     parenSP     = -1;
+    parenStack.resize(128);
 }
 
 inline void ScriptRun::reset(int32_t start, int32_t length)