Make more improvements

This change includes many bug fixes, for the NT polyfills, strings,
memory, boot, and math libraries which were discovered by adding more
tools for recreational programming, such as PC emulation. Lemon has also
been vendored because it works so well at parsing languages.

libc/bits/bits.h

@@ -45,9 +45,9 @@ unsigned long hamming(unsigned long, unsigned long) pureconst;
 #define ROL(w, k) ((w) << (k) | CheckUnsigned(w) >> (sizeof(w) * 8 - (k)))
 #define SAR(w, k) (((w) & ~(~0u >> (k))) | ((w) >> ((k) & (sizeof(w) * 8 - 1))))
 
-#define bitreverse8(X) (kReverseBits[(X)&0xff])
-#define bitreverse16(X)                      \
-  ((uint16_t)kReverseBits[(X)&0xff] << 010 | \
+#define bitreverse8(X) (kReverseBits[(uint8_t)(X)])
+#define bitreverse16(X)                          \
+  ((uint16_t)kReverseBits[(uint8_t)(X)] << 010 | \
    kReverseBits[((uint16_t)(X) >> 010) & 0xff])
 
 #define READ16LE(S)                             \

libc/bits/roundup.c

@@ -19,4 +19,6 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/macros.h"
 
-long(roundup)(long w, long k) { return ROUNDUP(w, k); }
+long(roundup)(long w, long k) {
+  return ROUNDUP(w, k);
+}