Fix nested references to 'ref' foreach variables.

These "walk around" the array being iterated over, so they're a bit trickier
than other variables to get right.

tests/mini/compile_rawvardeclinfinally.d

@@ -1 +1,8 @@
-void foo() { void delegate()[] bar; try {} finally { foreach (dg; bar) dg(); } }
+void foo() {
+    void delegate()[] bar;
+    try {
+    } finally {
+        foreach (dg; bar)
+            dg();
+    }
+}

tests/mini/foreach10.d

@@ -0,0 +1,19 @@
+module foreach10;
+
+extern(C) int printf(char*, ...);
+
+void main() {
+    char* last = null;
+    printf("The addresses should increment:\n");
+    foreach (ref c; "bar") {
+        auto a = {
+            printf("%x '%c'\n", c, c);
+            return &c;
+        };
+        auto nw = a();
+        printf("ptr = %p\n", nw);
+        if (last != null)
+            assert(nw == last+1);
+        last = nw;
+    }
+}

tests/mini/foreach11.d

@@ -0,0 +1,18 @@
+module foreach11;
+
+extern(C) int printf(char*, ...);
+
+void main() {
+    char* last = null;
+    printf("The addresses should remain constant:\n");
+    foreach (c; "bar") {
+        auto a = {
+            printf("%x '%c'\n", c, c);
+            printf("ptr = %p\n", &c);
+            if (last)
+                assert(last == &c);
+        };
+        a();
+        last = &c;
+    }
+}