Bug 794286 - ReconstructPcStack, Keep hidden stack depth only when following gotos. r=luke

js/src/jit-test/tests/basic/bug794286.js

@@ -0,0 +1,6 @@
+// |jit-test| error: TypeError
+for (var i = 0; i < 1; i++) {
+    let y
+    if (undefined) continue
+    undefined.e
+}

js/src/jsopcode.cpp

@@ -6431,6 +6431,7 @@ ReconstructPCStack(JSContext *cx, JSScript *script, jsbytecode *target,
             if (0 < jmpoff && pc + jmpoff <= target) {
                 pc += jmpoff;
                 oplen = 0;
+                /* Use the Hidden pc count if we follow the goto */
                 if (hpcdepth != unsigned(-1)) {
                     pcdepth = hpcdepth;
                     hpcdepth = unsigned(-1);
@@ -6438,8 +6439,11 @@ ReconstructPCStack(JSContext *cx, JSScript *script, jsbytecode *target,
                 continue;
             }
 
-            if (!script->hasTrynotes())
+            if (!script->hasTrynotes()) {
+                /* Use the normal pc count if continue after the goto */
+                hpcdepth = unsigned(-1);
                 continue;
+            }
 
             /*
              * If we do not follow a goto we look for another mean to continue