dtgex2: add 2 to iwork length to prevent OOB interaction in Dtgsy2

Author: soypat

SRC/dtgex2.f

@@ -254,7 +254,7 @@ SUBROUTINE DTGEX2( WANTQ, WANTZ, N, A, LDA, B, LDB, Q, LDQ, Z,
      $                   THRESHA, THRESHB
 *     ..
 *     .. Local Arrays ..
-      INTEGER            IWORK( LDST )
+      INTEGER            IWORK( LDST + 2 )
       DOUBLE PRECISION   AI( 2 ), AR( 2 ), BE( 2 ), IR( LDST, LDST ),
      $                   IRCOP( LDST, LDST ), LI( LDST, LDST ),
      $                   LICOP( LDST, LDST ), S( LDST, LDST ),