Clean up -Wdangling-assignment-gsl in clang and mlir

These are triggering after b037bce.

Author: d0k

clang-tools-extra/include-cleaner/lib/Analysis.cpp

@@ -85,8 +85,9 @@ analyze(llvm::ArrayRef<Decl *> ASTRoots,
   const auto MainFile = *SM.getFileEntryRefForID(SM.getMainFileID());
   llvm::DenseSet<const Include *> Used;
   llvm::StringMap<Header> Missing;
+  constexpr auto DefaultHeaderFilter = [](llvm::StringRef) { return false; };
   if (!HeaderFilter)
-    HeaderFilter = [](llvm::StringRef) { return false; };
+    HeaderFilter = DefaultHeaderFilter;
   OptionalDirectoryEntryRef ResourceDir =
       PP.getHeaderSearchInfo().getModuleMap().getBuiltinDir();
   walkUsed(ASTRoots, MacroRefs, PI, PP,

clang/tools/driver/driver.cpp

@@ -355,10 +355,12 @@ int clang_main(int Argc, char **Argv, const llvm::ToolContext &ToolContext) {
   if (!SetBackdoorDriverOutputsFromEnvVars(TheDriver))
     return 1;
 
+  auto ExecuteCC1WithContext =
+      [&ToolContext](SmallVectorImpl<const char *> &ArgV) {
+        return ExecuteCC1Tool(ArgV, ToolContext);
+      };
   if (!UseNewCC1Process) {
-    TheDriver.CC1Main = [ToolContext](SmallVectorImpl<const char *> &ArgV) {
-      return ExecuteCC1Tool(ArgV, ToolContext);
-    };
+    TheDriver.CC1Main = ExecuteCC1WithContext;
     // Ensure the CC1Command actually catches cc1 crashes
     llvm::CrashRecoveryContext::Enable();
   }

mlir/lib/Dialect/Affine/Utils/LoopUtils.cpp

@@ -919,8 +919,9 @@ static void generateUnrolledLoop(
   // 'forOp'.
   auto builder = OpBuilder::atBlockTerminator(loopBodyBlock);
 
+  constexpr auto defaultAnnotateFn = [](unsigned, Operation *, OpBuilder) {};
   if (!annotateFn)
-    annotateFn = [](unsigned, Operation *, OpBuilder) {};
+    annotateFn = defaultAnnotateFn;
 
   // Keep a pointer to the last non-terminator operation in the original block
   // so that we know what to clone (since we are doing this in-place).

mlir/lib/Dialect/SCF/Utils/Utils.cpp

@@ -329,8 +329,9 @@ static void generateUnrolledLoop(
   // 'forOp'.
   auto builder = OpBuilder::atBlockTerminator(loopBodyBlock);
 
+  constexpr auto defaultAnnotateFn = [](unsigned, Operation *, OpBuilder) {};
   if (!annotateFn)
-    annotateFn = [](unsigned, Operation *, OpBuilder) {};
+    annotateFn = defaultAnnotateFn;
 
   // Keep a pointer to the last non-terminator operation in the original block
   // so that we know what to clone (since we are doing this in-place).