target-microblaze: lwx/swx: first implementation

Signed-off-by: Peter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
diff --git a/target-microblaze/helper.c b/target-microblaze/helper.c
index 2412a58..74fce26 100644
--- a/target-microblaze/helper.c
+++ b/target-microblaze/helper.c
@@ -29,6 +29,7 @@
 void do_interrupt (CPUMBState *env)
 {
     env->exception_index = -1;
+    env->res_addr = RES_ADDR_NONE;
     env->regs[14] = env->sregs[SR_PC];
 }
 
@@ -116,6 +117,7 @@
     assert(!((env->iflags & D_FLAG) && (env->iflags & IMM_FLAG)));
     assert(!(env->iflags & (DRTI_FLAG | DRTE_FLAG | DRTB_FLAG)));
 /*    assert(env->sregs[SR_MSR] & (MSR_EE)); Only for HW exceptions.  */
+    env->res_addr = RES_ADDR_NONE;
     switch (env->exception_index) {
         case EXCP_HW_EXCP:
             if (!(env->pvr.regs[0] & PVR0_USE_EXC_MASK)) {