Make AARCH64 harder, better, faster, stronger

- Perform some housekeeping on scalar math function code
- Import ARM's Optimized Routines for SIMD string processing
- Upgrade to latest Chromium zlib and enable more SIMD optimizations

third_party/zlib/inffast_chunk.internal.h

@@ -0,0 +1,42 @@
+/* inffast_chunk.h -- header to use inffast_chunk.c
+ * Copyright (C) 1995-2003, 2010 Mark Adler
+ * Copyright (C) 2017 ARM, Inc.
+ * Copyright 2023 The Chromium Authors
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* WARNING: this file should *not* be used by applications. It is
+   part of the implementation of the compression library and is
+   subject to change. Applications should only use zlib.h.
+ */
+
+#include "third_party/zlib/inffast.internal.h"
+
+/* INFLATE_FAST_MIN_INPUT:
+   The minimum number of input bytes needed so that we can safely call
+   inflate_fast() with only one up-front bounds check. One
+   length/distance code pair (15 bits for the length code, 5 bits for length
+   extra, 15 bits for the distance code, 13 bits for distance extra) requires
+   reading up to 48 input bits. Additionally, in the same iteraction, we may
+   decode two literals from the root-table (requiring MIN_OUTPUT = 258 + 2).
+
+   Each root-table entry is up to 10 bits, for a total of 68 input bits each
+   iteraction.
+
+   The refill variant reads 8 bytes from the buffer at a time, and advances
+   the input pointer by up to 7 bytes, ensuring there are at least 56-bits
+   available in the bit-buffer. The technique was documented by Fabian Giesen
+   on his blog as variant 4 in the article 'Reading bits in far too many ways':
+   https://fgiesen.wordpress.com/2018/02/20/
+
+   In the worst case, we may refill twice in the same iteraction, requiring
+   MIN_INPUT = 8 + 7.
+*/
+#ifdef INFLATE_CHUNK_READ_64LE
+#undef INFLATE_FAST_MIN_INPUT
+#define INFLATE_FAST_MIN_INPUT 15
+#undef INFLATE_FAST_MIN_OUTPUT
+#define INFLATE_FAST_MIN_OUTPUT 260
+#endif
+
+void inflate_fast_chunk_(z_streamp strm, unsigned start);