[DwarfDebug] Add forward declarations of "<" operators [NFC]
The operators are defined in DwarfDebug.cpp but are
referenced in the struct definitions of FrameIndexExpr and
EntryValueInfo in DwarfDebug.h, and since they weren't
declared before, gcc warned with
[694/5646] Building CXX object lib/CodeGen/AsmPrinter/CMakeFiles/LLVMAsmPrinter.dir/DwarfDebug.cpp.o
../lib/CodeGen/AsmPrinter/DwarfDebug.cpp:273:6: warning: 'bool llvm::operator<(const llvm::FrameIndexExpr&, const llvm::FrameIndexExpr&)' has not been declared within 'llvm'
273 | bool llvm::operator<(const FrameIndexExpr &LHS, const FrameIndexExpr &RHS) {
| ^~~~
In file included from ../lib/CodeGen/AsmPrinter/DwarfDebug.cpp:13:
../lib/CodeGen/AsmPrinter/DwarfDebug.h:112:15: note: only here as a 'friend'
112 | friend bool operator<(const FrameIndexExpr &LHS, const FrameIndexExpr &RHS);
| ^~~~~~~~
../lib/CodeGen/AsmPrinter/DwarfDebug.cpp:278:6: warning: 'bool llvm::operator<(const llvm::EntryValueInfo&, const llvm::EntryValueInfo&)' has not been declared within 'llvm'
278 | bool llvm::operator<(const EntryValueInfo &LHS, const EntryValueInfo &RHS) {
| ^~~~
In file included from ../lib/CodeGen/AsmPrinter/DwarfDebug.cpp:13:
../lib/CodeGen/AsmPrinter/DwarfDebug.h:121:15: note: only here as a 'friend'
121 | friend bool operator<(const EntryValueInfo &LHS, const EntryValueInfo &RHS);
| ^~~~~~~~
GitOrigin-RevId: 23b8a19a1bce39d1e491e63d37b21ca8f6d2158f
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 52b342f..75649a7 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -103,6 +103,11 @@
class DbgVariable;
+bool operator<(const struct FrameIndexExpr &LHS,
+ const struct FrameIndexExpr &RHS);
+bool operator<(const struct EntryValueInfo &LHS,
+ const struct EntryValueInfo &RHS);
+
/// Proxy for one MMI entry.
struct FrameIndexExpr {
int FI;
