Export of internal Abseil changes

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6b5be2524a088d0f4e8475794dc71232a24e94d8 by Abseil Team <absl-team@google.com>:

Enable ABSL_HAVE_ATTRIBUTE_WEAK for Windows with Clang >= 9.0.0

The bug (https://bugs.llvm.org/show_bug.cgi?id=37598) motivated the workaround
was fixed in 9.0.0.

PiperOrigin-RevId: 365682074

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c16b7784978a370658dce6d82cb7055316a79bcc by Abseil Team <absl-team@google.com>:

Add IsFlat() evaluation to GetFlatAux for RingBuffer

PiperOrigin-RevId: 365666501

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c064eb686a3c036e093e71126c45f97d3a921569 by Abseil Team <absl-team@google.com>:

Implement C++11 compatible std::remove_cvref added in C++20

PiperOrigin-RevId: 365606639

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af2e7e055172da914e63c05308aedb68e197661e by Abseil Team <absl-team@google.com>:

Add IsFlat() support to CordRepRing

PiperOrigin-RevId: 365562090

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2cfeff9280f4967c4f828812bfe153b4e9cbabb7 by Abseil Team <absl-team@google.com>:

Make unit test for TryFlat on 'substring of rep' explicit

PiperOrigin-RevId: 365081382
GitOrigin-RevId: 6b5be2524a088d0f4e8475794dc71232a24e94d8
Change-Id: Ibb577748176217ce237614a6fe77c05375a97003

1 files changed, 5 insertions, 0 deletions

diff --git a/absl/strings/cord.cc b/absl/strings/cord.cc
index 93533757..1c03a618 100644
--- a/absl/strings/cord.cc
+++ b/absl/strings/cord.cc
@@ -1688,6 +1688,8 @@ absl::string_view Cord::FlattenSlowPath() {
   } else if (rep->tag == EXTERNAL) {
     *fragment = absl::string_view(rep->external()->base, rep->length);
     return true;
+  } else if (rep->tag == RING) {
+    return rep->ring()->IsFlat(fragment);
   } else if (rep->tag == SUBSTRING) {
     CordRep* child = rep->substring()->child;
     if (child->tag >= FLAT) {
@@ -1698,6 +1700,9 @@ absl::string_view Cord::FlattenSlowPath() {
       *fragment = absl::string_view(
           child->external()->base + rep->substring()->start, rep->length);
       return true;
+    } else if (child->tag == RING) {
+      return child->ring()->IsFlat(rep->substring()->start, rep->length,
+                                   fragment);
     }
   }
   return false;