Export of internal Abseil changes

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77cd6291781bc39e8472c706163d6951fe2ae573 by Derek Mauro <dmauro@google.com>:

absl::uint128: Use intrinsics for more operations when available

This change also inlines the division and modulus operators when
intrinsics are available for better code generation.

Fixes #987

PiperOrigin-RevId: 389895706

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fa23339584599e07ebcb4d0a857e2553b017757c by Abseil Team <absl-team@google.com>:

only hide retired flags if human-readable output is requested

PiperOrigin-RevId: 389835452

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f1111f2b88359d4b253d4d81681c8a488458a36e by Martijn Vels <mvels@google.com>:

Add helpers IsFlat(), IsExternal(), etc to improve readability

PiperOrigin-RevId: 389779333

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785b8712261e41695ebeeb64b4317f93b37adc11 by Martijn Vels <mvels@google.com>:

Split off 'concat' and 'btree' RepMemoryUsageLeaf and RepMemoryUsageDataEdge

PiperOrigin-RevId: 389701120

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5264bffebffc2b377bf7e18f0ce69a3ed38c6629 by CJ Johnson <johnsoncj@google.com>:

Eagerly destroy `Callback` in `absl::Cleanup`

PiperOrigin-RevId: 389678813

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a05312f0668458e97c50ca932c8f974c1508ebf2 by Abseil Team <absl-team@google.com>:

Have one instance of empty_group per program, rather than one per translation unit.

https://stackoverflow.com/questions/185624/static-variables-in-an-inlined-function

PiperOrigin-RevId: 389185845
GitOrigin-RevId: 77cd6291781bc39e8472c706163d6951fe2ae573
Change-Id: Iac8d9cb27707a9562c831c77a552d1fb4bb0405f

2 files changed, 8 insertions, 6 deletions

diff --git a/absl/container/internal/raw_hash_set.cc b/absl/container/internal/raw_hash_set.cc
index a5dee6aa..e219956f 100644
--- a/absl/container/internal/raw_hash_set.cc
+++ b/absl/container/internal/raw_hash_set.cc
@@ -23,6 +23,12 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace container_internal {
 
+ABSL_CONST_INIT ABSL_DLL alignas(16) const ctrl_t kEmptyGroup[16] = {
+    ctrl_t::kSentinel, ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty,
+    ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty,
+    ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty,
+    ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty};
+
 constexpr size_t Group::kWidth;
 
 // Returns "random" seed.
diff --git a/absl/container/internal/raw_hash_set.h b/absl/container/internal/raw_hash_set.h
index d7783263..bafafd46 100644
--- a/absl/container/internal/raw_hash_set.h
+++ b/absl/container/internal/raw_hash_set.h
@@ -291,13 +291,9 @@ static_assert(ctrl_t::kDeleted == static_cast<ctrl_t>(-2),
 
 // A single block of empty control bytes for tables without any slots allocated.
 // This enables removing a branch in the hot path of find().
+ABSL_DLL extern const ctrl_t kEmptyGroup[16];
 inline ctrl_t* EmptyGroup() {
-  alignas(16) static constexpr ctrl_t empty_group[] = {
-      ctrl_t::kSentinel, ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty,
-      ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty,
-      ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty,
-      ctrl_t::kEmpty,    ctrl_t::kEmpty, ctrl_t::kEmpty, ctrl_t::kEmpty};
-  return const_cast<ctrl_t*>(empty_group);
+  return const_cast<ctrl_t*>(kEmptyGroup);
 }
 
 // Mixes a randomly generated per-process seed with `hash` and `ctrl` to