[modularize] Use default member initialization for Location (NFC) (#139384)

Author: kazutakahirata

clang-tools-extra/modularize/Modularize.cpp

@@ -379,11 +379,11 @@ getModularizeArgumentsAdjuster(DependencyMap &Dependencies) {
 // somewhere into Tooling/ in mainline
 struct Location {
   OptionalFileEntryRef File;
-  unsigned Line, Column;
+  unsigned Line = 0, Column = 0;
 
-  Location() : File(), Line(), Column() {}
+  Location() = default;
 
-  Location(SourceManager &SM, SourceLocation Loc) : File(), Line(), Column() {
+  Location(SourceManager &SM, SourceLocation Loc) {
     Loc = SM.getExpansionLoc(Loc);
     if (Loc.isInvalid())
       return;