[memprof] Use front instead of begin in a unit test (NFC)

[kazutakahirata]

"front" allows us to drop a dereference.

[llvmbot]

@llvm/pr-subscribers-pgo

Author: Kazu Hirata (kazutakahirata)

Changes

"front" allows us to drop a dereference.

---

Full diff: https://github.com/llvm/llvm-project/pull/119501.diff

1 Files Affected:

• (modified) llvm/unittests/ProfileData/MemProfTest.cpp (+1-1)

diff --git a/llvm/unittests/ProfileData/MemProfTest.cpp b/llvm/unittests/ProfileData/MemProfTest.cpp
index 093b3a26b5f872..e121bae8b4481b 100644
--- a/llvm/unittests/ProfileData/MemProfTest.cpp
+++ b/llvm/unittests/ProfileData/MemProfTest.cpp
@@ -747,7 +747,7 @@ TEST(MemProf, YAMLParser) {
 
   // Verify the entire contents of MemProfData.Records.
   ASSERT_THAT(MemProfData.Records, SizeIs(1));
-  const auto &[GUID, Record] = *MemProfData.Records.begin();
+  const auto &[GUID, Record] = MemProfData.Records.front();
   EXPECT_EQ(GUID, 0xdeadbeef12345678ULL);
   ASSERT_THAT(Record.AllocSites, SizeIs(2));
   EXPECT_EQ(Record.AllocSites[0].CSId, hashCallStack(CS1));