Change: relocated Tags to decrease padding.

64-bit

The problematic areas are:

SymInfo (6 bytes) → followed by a 2-byte gap
Origin (2 bytes) → followed by a 2-byte gap before StringRef
Tags (4 bytes) → followed by a 4-byte gap before SmallVector
Flags at the end → 7 bytes end padding

32-bit

SymInfo → 2-byte gap
Origin → 2-byte gap
Flags at the end → 3 bytes end padding

This patch reduces paddings:
64-bit: 240 -> 232 (-8 Bytes, ~3.3%)
32-bit: 144 -> 140 (-4 Bytes, ~2.8%)

Author: ratzdi

clang-tools-extra/clangd/index/Symbol.h

@@ -51,6 +51,8 @@ struct Symbol {
   SymbolID ID;
   /// The symbol information, like symbol kind.
   index::SymbolInfo SymInfo = index::SymbolInfo();
+  /// Where this symbol came from. Usually an index provides a constant value.
+  SymbolOrigin Origin = SymbolOrigin::Unknown;
   /// The unqualified name of the symbol, e.g. "bar" (for ns::bar).
   llvm::StringRef Name;
   /// The containing namespace. e.g. "" (global), "ns::" (top-level namespace).
@@ -70,8 +72,10 @@ struct Symbol {
   /// The number of translation units that reference this symbol from their main
   /// file. This number is only meaningful if aggregated in an index.
   unsigned References = 0;
-  /// Where this symbol came from. Usually an index provides a constant value.
-  SymbolOrigin Origin = SymbolOrigin::Unknown;
+  /// Symbol tags for LSP protocol (Deprecated, Static, Virtual, Abstract,
+  /// Final, ReadOnly, Public, Protected, Private, Declaration, Definition).
+  /// This is a bitmask where each bit represents a SymbolTag.
+  SymbolTags Tags = 0;
   /// A brief description of the symbol that can be appended in the completion
   /// candidate list. For example, "(X x, Y y) const" is a function signature.
   /// Only set when the symbol is indexed for completion.
@@ -97,11 +101,6 @@ struct Symbol {
   /// Only set when the symbol is indexed for completion.
   llvm::StringRef Type;
 
-  /// Symbol tags for LSP protocol (Deprecated, Static, Virtual, Abstract,
-  /// Final, ReadOnly, Public, Protected, Private, Declaration, Definition).
-  /// This is a bitmask where each bit represents a SymbolTag.
-  SymbolTags Tags = 0;
-
   enum IncludeDirective : uint8_t {
     Invalid = 0,
     /// `#include "header.h"`