[clangd] Explicitly initialize all primitive fields in Protocol.h

Summary:
Some of the existing structs had primimtive fields that were
not explicitly initialized on construction.
After this commit every struct consistently sets a defined value for
every field when default-initialized.

Reviewers: hokein, ioeric, sammccall

Reviewed By: sammccall

Subscribers: klimek, cfe-commits, jkorous-apple

Differential Revision: https://reviews.llvm.org/D43230

llvm-svn: 325113
diff --git a/clang-tools-extra/clangd/SourceCode.cpp b/clang-tools-extra/clangd/SourceCode.cpp
index e2d9f19..7ef3700 100644
--- a/clang-tools-extra/clangd/SourceCode.cpp
+++ b/clang-tools-extra/clangd/SourceCode.cpp
@@ -33,7 +33,10 @@
   size_t PrevNL = Before.rfind('\n');
   size_t StartOfLine = (PrevNL == StringRef::npos) ? 0 : (PrevNL + 1);
   // FIXME: officially character counts UTF-16 code units, not UTF-8 bytes!
-  return {Lines, static_cast<int>(Offset - StartOfLine)};
+  Position Pos;
+  Pos.line = Lines;
+  Pos.character = static_cast<int>(Offset - StartOfLine);
+  return Pos;
 }
 
 } // namespace clangd