[Serialization] Use StringRef::substr (NFC)

[kazutakahirata]

StringRef::substr is shorter here because we can rely on its default
second parameter.

[llvmbot]

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clang-modules

Author: Kazu Hirata (kazutakahirata)

Changes

StringRef::substr is shorter here because we can rely on its default
second parameter.

---

Full diff: https://github.com/llvm/llvm-project/pull/139678.diff

1 Files Affected:

• (modified) clang/lib/Serialization/ASTWriter.cpp (+1-1)

diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index c4c0603839c62..7de510c85bfed 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -1237,7 +1237,7 @@ ASTWriter::createSignature() const {
   Hasher.update(
       AllBytes.slice(UnhashedControlBlockRange.second, ASTBlockRange.first));
   //  3. After the AST block.
-  Hasher.update(AllBytes.slice(ASTBlockRange.second, StringRef::npos));
+  Hasher.update(AllBytes.substr(ASTBlockRange.second));
   ASTFileSignature Signature = ASTFileSignature::create(Hasher.result());
 
   return std::make_pair(ASTBlockHash, Signature);