Export of internal Abseil changes

--
ea5599482a5120800f060c6d41334dbdbabc3941 by Mark Barolak <mbar@google.com>:

Import of CCTZ from GitHub.

PiperOrigin-RevId: 329715235

--
e897a582bed3aff509b98e5da0711b2afd15ed17 by Tom Manshreck <shreck@google.com>:

* Update Status with overview
* Move public API helper functions out of "Implementation Details"
* Add documentation to Status Codes

PiperOrigin-RevId: 329595541

--
f93b28596f24fa005606565e0a8a4dabe260b01c by Abseil Team <absl-team@google.com>:

Fix -Wextra-semi issues.

ABSL_COMPARE_INLINE_xxx_DECL may expand to nothing.
That produces structs that have only semicolon inside class declaration.
such struct is not a valid c++ code and fails to compile when -Wextra-semi is turned on.

PiperOrigin-RevId: 329564534
GitOrigin-RevId: ea5599482a5120800f060c6d41334dbdbabc3941
Change-Id: Icc9944c3ec8303abc26a167c2ba7c91e59a4877f

absl/time/internal/cctz/src/time_zone_lookup_test.cc

@@ -1007,7 +1007,11 @@ TEST(MakeTime, SysSecondsLimits) {
     const time_zone cut = LoadZone("libc:UTC");
     const year_t max_tm_year = year_t{std::numeric_limits<int>::max()} + 1900;
     tp = convert(civil_second(max_tm_year, 12, 31, 23, 59, 59), cut);
+#if defined(__FreeBSD__) || defined(__OpenBSD__)
+    // The BSD gmtime_r() fails on extreme positive tm_year values.
+#else
     EXPECT_EQ("2147485547-12-31T23:59:59+00:00", format(RFC3339, tp, cut));
+#endif
     const year_t min_tm_year = year_t{std::numeric_limits<int>::min()} + 1900;
     tp = convert(civil_second(min_tm_year, 1, 1, 0, 0, 0), cut);
     EXPECT_EQ("-2147481748-01-01T00:00:00+00:00", format(RFC3339, tp, cut));

absl/types/compare.h

@@ -86,7 +86,8 @@ enum class ncmp : value_type { unordered = -127 };
 // incomplete types so they need to be defined after the types are complete.
 #ifdef __cpp_inline_variables
 
-#define ABSL_COMPARE_INLINE_BASECLASS_DECL(name)
+// A no-op expansion that can be followed by a semicolon at class level.
+#define ABSL_COMPARE_INLINE_BASECLASS_DECL(name) static_assert(true, "")
 
 #define ABSL_COMPARE_INLINE_SUBCLASS_DECL(type, name) \
   static const type name
@@ -99,7 +100,8 @@ enum class ncmp : value_type { unordered = -127 };
 #define ABSL_COMPARE_INLINE_BASECLASS_DECL(name) \
   ABSL_CONST_INIT static const T name
 
-#define ABSL_COMPARE_INLINE_SUBCLASS_DECL(type, name)
+// A no-op expansion that can be followed by a semicolon at class level.
+#define ABSL_COMPARE_INLINE_SUBCLASS_DECL(type, name) static_assert(true, "")
 
 #define ABSL_COMPARE_INLINE_INIT(type, name, init) \
   template <typename T>                            \