Make numerous improvements

- Python static hello world now 1.8mb
- Python static fully loaded now 10mb
- Python HTTPS client now uses MbedTLS
- Python REPL now completes import stmts
- Increase stack size for Python for now
- Begin synthesizing posixpath and ntpath
- Restore Python \N{UNICODE NAME} support
- Restore Python NFKD symbol normalization
- Add optimized code path for Intel SHA-NI
- Get more Python unit tests passing faster
- Get Python help() pagination working on NT
- Python hashlib now supports MbedTLS PBKDF2
- Make memcpy/memmove/memcmp/bcmp/etc. faster
- Add Mersenne Twister and Vigna to LIBC_RAND
- Provide privileged __printf() for error code
- Fix zipos opendir() so that it reports ENOTDIR
- Add basic chmod() implementation for Windows NT
- Add Cosmo's best functions to Python cosmo module
- Pin function trace indent depth to that of caller
- Show memory diagram on invalid access in MODE=dbg
- Differentiate stack overflow on crash in MODE=dbg
- Add stb_truetype and tools for analyzing font files
- Upgrade to UNICODE 13 and reduce its binary footprint
- COMPILE.COM now logs resource usage of build commands
- Start implementing basic poll() support on bare metal
- Set getauxval(AT_EXECFN) to GetModuleFileName() on NT
- Add descriptions to strerror() in non-TINY build modes
- Add COUNTBRANCH() macro to help with micro-optimizations
- Make error / backtrace / asan / memory code more unbreakable
- Add fast perfect C implementation of μ-Law and a-Law audio codecs
- Make strtol() functions consistent with other libc implementations
- Improve Linenoise implementation (see also github.com/jart/bestline)
- COMPILE.COM now suppresses stdout/stderr of successful build commands

libc/calls/sigaction.c

@@ -49,12 +49,12 @@
     autotype((S2).B) b = (typeof((S2).B))(S1).B;           \
     autotype((S2).C) c = (typeof((S2).C))(S1).C;           \
     typeof((S2).D) d;                                      \
-    memset(&d, 0, sizeof(d));                              \
+    bzero(&d, sizeof(d));                                  \
     memcpy(&d, &((S1).D), MIN(sizeof(d), sizeof((S1).D))); \
     (S2).A = a;                                            \
     (S2).B = b;                                            \
     (S2).C = c;                                            \
-    memset(&((S2).D), 0, sizeof((S2).D));                  \
+    bzero(&((S2).D), sizeof((S2).D));                      \
     memcpy(&((S2).D), &d, MIN(sizeof(d), sizeof((S2).D))); \
   } while (0);
 #endif
@@ -217,7 +217,7 @@ int(sigaction)(int sig, const struct sigaction *act, struct sigaction *oldact) {
     }
   } else {
     if (oldact) {
-      memset(oldact, 0, sizeof(*oldact));
+      bzero(oldact, sizeof(*oldact));
     }
     rc = 0;
   }