Import C++ Standard Template Library

You can now use the hardest fastest and most dangerous language there is
with Cosmopolitan. So far about 75% of LLVM libcxx has been added. A few
breaking changes needed to be made to help this go smoothly.

- Rename nothrow to dontthrow
- Rename nodiscard to dontdiscard
- Add some libm functions, e.g. lgamma, nan, etc.
- Change intmax_t from int128 to int64 like everything else
- Introduce %jjd formatting directive for int128_t
- Introduce strtoi128(), strtou128(), etc.
- Rename bsrmax() to bsr128()

Some of the templates that should be working currently are std::vector,
std::string, std::map, std::set, std::deque, etc.

libc/testlib/ezbench.h

@@ -7,6 +7,7 @@
 #include "libc/testlib/testlib.h"
 #include "libc/time/time.h"
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
+COSMOPOLITAN_C_START_
 
 #define EZBENCH(INIT, EXPR) EZBENCH2(#EXPR, INIT, EXPR)
 
@@ -189,5 +190,7 @@ void __testlib_ezbenchreport_n(const char *, char, size_t, uint64_t);
 #define EZBENCH_N(NAME, N, EXPR)        (void)0
 #define EZBENCH_K(NAME, K, EXPR)        (void)0
 #endif
+
+COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
 #endif /* COSMOPOLITAN_LIBC_TESTLIB_EZBENCH_H_ */

libc/testlib/formatint.c

@@ -25,7 +25,7 @@
 static size_t sbufi_;
 static char sbufs_[2][256];
 
-nodiscard testonly char *testlib_formatint(intptr_t x) {
+dontdiscard testonly char *testlib_formatint(intptr_t x) {
   char *str = sbufi_ < ARRAYLEN(sbufs_) ? sbufs_[sbufi_++] : malloc(256);
   char *p = str;
   p += sprintf(p, "%ld\t(or %#lx", x, x);

libc/testlib/formatrange.c

@@ -19,6 +19,6 @@
 #include "libc/testlib/testlib.h"
 #include "libc/x/x.h"
 
-nodiscard testonly char *testlib_formatrange(intptr_t beg, intptr_t end) {
+dontdiscard testonly char *testlib_formatrange(intptr_t beg, intptr_t end) {
   return xasprintf("[%#ld,%#ld]", beg, end);
 }

libc/testlib/formatstr.c

@@ -24,7 +24,7 @@
 /**
  * Turns string into code.
  */
-nodiscard testonly char *testlib_formatstr(size_t cw, const void *s, int n) {
+dontdiscard testonly char *testlib_formatstr(size_t cw, const void *s, int n) {
   if (s) {
     switch (cw) {
       case 1: