Integrate LLVM at llvm/llvm-project@f6f944e77f74

Updates LLVM usage to match
[f6f944e77f74](https://github.com/llvm/llvm-project/commit/f6f944e77f74)

PiperOrigin-RevId: 574085237
Change-Id: I78f364d00535921ddcafa6b20aaa15d3b00d48d1

nullability/test/convergence.cc

diff --git a/nullability/test/convergence.cc b/nullability/test/convergence.cc
index 8c3be15..348badf 100644
--- a/nullability/test/convergence.cc
+++ b/nullability/test/convergence.cc
@@ -134,8 +134,7 @@
     int* _Nullable GetNext();
     void target() {
       for (int* p = GetFirst(); p != nullptr; p = GetNext()) {
-        // TODO: False positive. This dereference is safe.
-        *p;  // [[unsafe]]
+        *p;
       }
     }
   )cc"));
@@ -255,8 +254,7 @@
     void target() {
       int* p;
       while ((p = GetNext())) {
-        // TODO: False positive. This dereference is safe.
-        *p;  // [[unsafe]]
+        *p;
       }
     }
   )cc"));
@@ -269,8 +267,7 @@
     void target() {
       int* _Nullable p = GetFirst();
       while ((p = GetNext()) != nullptr) {
-        // TODO: False positive. This dereference is safe.
-        *p;  // [[unsafe]]
+        *p;
       }
     }
   )cc"));