[Runtime][Win32] Further tweaks to SymbolInfo.cpp and Errors.cpp.

Fix an unused variable warning in `Errors.cpp`.

Use brace initialization syntax in `SymbolInfo.cpp` rather than using
a constructor call.

rdar://130992923

Author: al45tair

stdlib/public/runtime/Errors.cpp

@@ -106,7 +106,7 @@ static bool getSymbolNameAddr(llvm::StringRef libraryName,
 
   // UnDecorateSymbolName() will not fail for Swift symbols, so detect them
   // up-front and let Swift handle them.
-  if (!Demangle::isMangledName(syminfo.getSymbolName())) {
+  if (!Demangle::isMangledName(szSymbolName)) {
     char szUndName[1024];
     DWORD dwResult;
     dwResult = _swift_win32_withDbgHelpLibrary([&] (HANDLE hProcess) -> DWORD {
@@ -119,7 +119,7 @@ static bool getSymbolNameAddr(llvm::StringRef libraryName,
       dwFlags |= UNDNAME_32_BIT_DECODE;
 #endif
 
-      return UnDecorateSymbolName(syminfo.getSymbolName(), szUndName,
+      return UnDecorateSymbolName(szSymbolName, szUndName,
                                   sizeof(szUndName), dwFlags);
     });
 

stdlib/public/runtime/SymbolInfo.cpp

@@ -72,8 +72,6 @@ const void *SymbolInfo::getSymbolAddress() const {
 struct Win32ModuleInfo {
   const char *name;
   const void *base;
-
-  Win32ModuleInfo(const char *n, const void *b) : name(n), base(b) {}
 };
 
 // Get the filename and base of the module that contains the specified
@@ -117,17 +115,17 @@ static Win32ModuleInfo moduleInfoFromAddress(const void *address) {
       if (pwszFileName != wszBuffer)
         ::free(pwszFileName);
 
-      return Win32ModuleInfo(::strdup("<unknown>"), mi.lpBaseOfDll);
+      return { ::strdup("<unknown>"), mi.lpBaseOfDll };
     }
 
     const char *result = _swift_win32_copyUTF8FromWide(pwszFileName);
 
     if (pwszFileName != wszBuffer)
       ::free((void *)pwszFileName);
 
-    return Win32ModuleInfo(result, mi.lpBaseOfDll);
+    return { result, mi.lpBaseOfDll };
   } else {
-    return Win32ModuleInfo(::strdup("<unknown>"), nullptr);
+    return { ::strdup("<unknown>"), nullptr };
   }
 }
 #endif