#32: more fixes

This change fixes:
 - 32 bit v4.x node binaries with improper JSTypedArray length offset.
 - v4.0.0 and v4.1.1 node binaries that miss Map's bit_field3's type
   metadata by hardcoding its type.

src/mdb_v8.c

@@ -473,9 +473,15 @@ static v8_offset_t v8_offsets[] = {
 	    "SlicedString", "parent", B_TRUE },
 	{ &V8_OFF_STRING_LENGTH,
 	    "String", "length" },
+#ifdef _LP64
 	{ &V8_OFF_JSTYPEDARRAY_LENGTH,
 	    "JSTypedArray", "length",
 	    B_FALSE, V8_CONSTANT_FALLBACK(4, 5), 55 },
+#else
+	{ &V8_OFF_JSTYPEDARRAY_LENGTH,
+	    "JSTypedArray", "length",
+	    B_FALSE, V8_CONSTANT_FALLBACK(4, 5), 27 },
+#endif
 };
 
 static int v8_noffsets = sizeof (v8_offsets) / sizeof (v8_offsets[0]);
@@ -1020,6 +1026,8 @@ conf_update_field(v8_cfg_t *cfgp, const char *symbol)
 	intptr_t offset;
 	char *pp, *qq, *tt;
 	char buf[128];
+	int is_map_bitfield3_smi = 0;
+	int is_v8_bitfield3_actually_int = 0;
 
 	(void) strlcpy(buf, symbol, sizeof (buf));
 
@@ -1038,11 +1046,28 @@ conf_update_field(v8_cfg_t *cfgp, const char *symbol)
 	    (flp = conf_field_create(clp, qq, (size_t)offset)) == NULL)
 		return (-1);
 
-	if (strcmp(tt, "int") == 0)
-		flp->v8f_isbyte = B_TRUE;
+	is_map_bitfield3_smi = strcmp(pp, "Map") == 0 &&
+	    strcmp(qq, "bit_field3") == 0 && strcmp(tt, "SMI") == 0;
 
-	if (strcmp(tt, "char") == 0)
+	/*
+	 * node v4.0.0 and v4.1.0 were released without the proper post-mortem
+	 * metadata for Map's bit_field3 type, so we hardcode its actual type
+	 * when V8's version is between the version that introduced the change
+	 * from SMI to int and the version where the proper metadata was added
+	 * (inclusive, since several node versions with the same V8 version
+	 * exist and some of them have the proper metadata, some of them don't).
+	 */
+	if (is_map_bitfield3_smi)
+		is_v8_bitfield3_actually_int =
+		    (v8_major == 3 && v8_minor >= 28) ||
+		    (v8_major == 4 && v8_minor <= 5);
+
+	if (strcmp(tt, "int") == 0 ||
+	    (is_map_bitfield3_smi && is_v8_bitfield3_actually_int)) {
+		flp->v8f_isbyte = B_TRUE;
+	} else if (strcmp(tt, "char") == 0) {
 		flp->v8f_isstr = B_TRUE;
+	}
 
 	return (0);
 }