Roll libxml to 3939178e4cb797417ff033b1e04ab4b038e224d9

Removes a few patches fixed upstream:
https://git.gnome.org/browse/libxml2/commit/?id=e26630548e7d138d2c560844c43820b6767251e3
https://git.gnome.org/browse/libxml2/commit/?id=94691dc884d1a8ada39f073408b4bb92fe7fe882

Stops using the NOXXE flag which was reverted upstream:
https://git.gnome.org/browse/libxml2/commit/?id=030b1f7a27c22f9237eddca49ec5e620b6258d7d

Changes the patch to uri.c to not add limits.h, which is included
upstream.

Bug: 722079
Change-Id: I4b8449ed33f95de23c54c2cde99970c2df2781ac
Reviewed-on: https://chromium-review.googlesource.com/535233
Reviewed-by: Scott Graham <scottmg@chromium.org>
Commit-Queue: Dominic Cooney <dominicc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#480755}
htmlCheckAutoClose(const xmlChar * newtag, const xmlChar * oldtag)
{
    int i, indx;
    const char **closed = NULL;

    if (htmlStartCloseIndexinitialized == 0)
        htmlInitAutoClose();

    /* inefficient, but not a big deal */
    for (indx = 0; indx < 100; indx++) {
        closed = htmlStartCloseIndex[indx];
        if (closed == NULL)
            return (0);
        if (xmlStrEqual(BAD_CAST * closed, newtag))
            break;
    }

    i = closed - htmlStartClose;
    i++;
    while (htmlStartClose[i] != NULL) {
        if (xmlStrEqual(BAD_CAST htmlStartClose[i], oldtag)) {
            return (1);
        }
        i++;
    }
    return (0);
}

htmlCheckAutoClose(const xmlChar * newtag, const xmlChar * oldtag)
{
    int i, indx;
    const char **closed = NULL;

    if (htmlStartCloseIndexinitialized == 0)
        htmlInitAutoClose();

    /* inefficient, but not a big deal */
    for (indx = 0; indx < 100; indx++) {
        closed = htmlStartCloseIndex[indx];
        if (closed == NULL)
            return (0);
        if (xmlStrEqual(BAD_CAST * closed, newtag))
            break;
    }

    i = closed - htmlStartClose;
    i++;
    while (htmlStartClose[i] != NULL) {
        if (xmlStrEqual(BAD_CAST htmlStartClose[i], oldtag)) {
            return (1);
        }
        i++;
    }
    return (0);
}
