[clang] [clang-format] Make ignored files unformatted instead of empty. (PR #170416)

[via cfe-commits]

================
@@ -401,8 +401,12 @@ class ClangFormatDiagConsumer : public DiagnosticConsumer {
 };
 
 // Returns true on error.
-static bool format(StringRef FileName, bool ErrorOnIncompleteFormat = false) {
+static bool format(StringRef FileName, bool ErrorOnIncompleteFormat,
+                   bool IsIgnored) {
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owenca wrote:

```suggestion
static bool format(StringRef FileName, bool ErrorOnIncompleteFormat) {
```
And leave the function body alone.

https://github.com/llvm/llvm-project/pull/170416