Export of internal Abseil changes

--
03700706d80f0939e2b5b8c02a326f045b643730 by Abseil Team <absl-team@google.com>:

Reduced latency and code-size of some InlinedVector methods:

1. Simpler fast path for push_back/emplace_back.
2. Do not inline slow path of push-back/emplace_back.
3. Simplify resize implementation.

Performance:
A simple benchmark that does the following per iteration:

```
push_back on an InlinedVector<int64>
push_back on an InlinedVector<bool>
```

Sees iteration time go from 4.3ns to 2.8ns and code size shrink from 1129 bytes to 175 bytes.

PiperOrigin-RevId: 343335635

--
16f74277a9e8bf228c164b053da8b8098f76de62 by Derek Mauro <dmauro@google.com>:

Internal change

PiperOrigin-RevId: 343332753

--
886b6d5d0244783d309e34f03c21710f411e3cb3 by Abseil Team <absl-team@google.com>:

Optimize `Status::Status`: When creating a status, we currently create an empty struct first, then assign fields. This is suboptimal: https://screenshot.googleplex.com/5HqDuFBKUEqrVgy.

Relevant Benchmarks:
```
BM_StatusCopyError_Deep/threads:1              26.9ns ±13%   21.2ns ±16%  -21.46%  (p=0.000 n=15+15)
BM_StatusCopyError_Deep/threads:2              32.0ns ±30%   25.6ns ±37%  -20.17%  (p=0.004 n=15+14)
BM_StatusCopyError_Deep/threads:4              37.4ns ±84%   30.6ns ±58%  -18.26%  (p=0.029 n=15+15)
BM_StatusCopyError_Deep/threads:8              47.2ns ±33%   33.5ns ±56%  -28.91%  (p=0.000 n=15+14)
```

PiperOrigin-RevId: 343303312

--
2f9d945654292e8e52cad410fa41dae794cff42c by Abseil Team <absl-team@google.com>:

Set SOVERSION for the installed libraries

PiperOrigin-RevId: 343287682

--
600bbfffe91cfbdc60b43cdad5619258298d0b0d by Abseil Team <absl-team@google.com>:

Fix a typo in a comment (than -> that)

PiperOrigin-RevId: 343187724

--
310c82cd97b3f1f0d1ee93a0ee2b0aee828b2a93 by Abseil Team <absl-team@google.com>:

Simplify unaligned memory access functions.

The #ifdef to produce calls to __sanitizer_unaligned_load16 etc were needed in past versions of this code, when we were lying to the compiler about the alignment of the loads/stores, by using a reinterpret_cast.

However, a year ago, absl switched to simply use memcpy. Sanitizers support this correctly by default, nothing extra is required.

PiperOrigin-RevId: 343159883

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bdf6fcf99180c371fda6ba8af82fd44656e372fa by Gennadiy Rozental <rogeeff@google.com>:

Migrate usage flags to global variables instead of modeling them as Abseil Flags.

Also introduce new semantic for --help=substring command line argument.

PiperOrigin-RevId: 343019883
GitOrigin-RevId: 03700706d80f0939e2b5b8c02a326f045b643730
Change-Id: I4ad40dfa9606f8b8bfb2d91fd09e327105311bfb

1 files changed, 31 insertions, 9 deletions

diff --git a/absl/flags/internal/usage.h b/absl/flags/internal/usage.h
index 619ccceb..c0bcac57 100644
--- a/absl/flags/internal/usage.h
+++ b/absl/flags/internal/usage.h
@@ -66,17 +66,39 @@ void FlagsHelp(std::ostream& out, absl::string_view filter,
 int HandleUsageFlags(std::ostream& out,
                      absl::string_view program_usage_message);
 
+// --------------------------------------------------------------------
+// Globals representing usage reporting flags
+
+enum class HelpMode {
+  kNone,
+  kImportant,
+  kShort,
+  kFull,
+  kPackage,
+  kMatch,
+  kVersion,
+  kOnlyCheckArgs
+};
+
+// Returns substring to filter help output (--help=substr argument)
+std::string GetFlagsHelpMatchSubstr();
+// Returns the requested help mode.
+HelpMode GetFlagsHelpMode();
+// Returns the requested help format.
+HelpFormat GetFlagsHelpFormat();
+
+// These are corresponding setters to the attributes above.
+void SetFlagsHelpMatchSubstr(absl::string_view);
+void SetFlagsHelpMode(HelpMode);
+void SetFlagsHelpFormat(HelpFormat);
+
+// Deduces usage flags from the input argument in a form --name=value or
+// --name. argument is already split into name and value before we call this
+// function.
+bool DeduceUsageFlags(absl::string_view name, absl::string_view value);
+
 }  // namespace flags_internal
 ABSL_NAMESPACE_END
 }  // namespace absl
 
-ABSL_DECLARE_FLAG(bool, help);
-ABSL_DECLARE_FLAG(bool, helpfull);
-ABSL_DECLARE_FLAG(bool, helpshort);
-ABSL_DECLARE_FLAG(bool, helppackage);
-ABSL_DECLARE_FLAG(bool, version);
-ABSL_DECLARE_FLAG(bool, only_check_args);
-ABSL_DECLARE_FLAG(std::string, helpon);
-ABSL_DECLARE_FLAG(std::string, helpmatch);
-
 #endif  // ABSL_FLAGS_INTERNAL_USAGE_H_