Avoid unicode filename

This is similar to 53e9d3e.

Over at https://github.com/cockroachdb/cockroach, we use bazel and it
chokes on this file:

```
java.io.IOException: Error extracting
[...]/com_github_maruel_panicparse_v2-v2.2.1.zip to [...]:
[...]/com_github_maruel_panicparse_v2/cmd/panic/internal/utf8/?tf8.go
(Illegal byte sequence)
```

which is why we're on a fork so far. It would be nice to avoid this.

There is an (eternal, it seems) [upstream discussion], so there is
little home of bazel starting to support non-unicode filenames.

I wonder if the loss in test coverage (if any) is acceptable in return
for avoiding build problems like the ones we've been seeing.

[upstream discussion]: bazelbuild/bazel#374

cmd/panic/internal/utf8/ùtf8.go → cmd/panic/internal/utf8/utf8.go

@@ -3,6 +3,9 @@
 // that can be found in the LICENSE file.
 
 // Package ùtf8 tests a package and function with non-ASCII names.
+//
+// The filename itself does not contain unicode as this causes issues
+// importing panicparse under bazel. For more context, see PR #78.
 package ùtf8
 
 // Strùct is a totally normal structure with a totally normal name.

stack/context_test.go

@@ -2023,7 +2023,7 @@ func testPanicUTF8(t *testing.T, s *Snapshot, b *bytes.Buffer, ppDir string) {
 							),
 							// See TestCallUTF8 in stack_test.go for exercising the methods on
 							// Call in this situation.
-							pathJoin(ppDir, "internal", "utf8", "ùtf8.go"),
+							pathJoin(ppDir, "internal", "utf8", "utf8.go"),
 							10),
 						newCallLocal("main.glob..func21", Args{}, pathJoin(ppDir, "main.go"), 322),
 						newCallLocal("main.main", Args{}, pathJoin(ppDir, "main.go"), 340),

stack/stack_test.go

@@ -163,11 +163,11 @@ func TestCallPkg(t *testing.T) {
 			// See testPanicUTF8 in context_test.go.
 			name:         "UTF8",
 			f:            "github.com/maruel/panicparse/cmd/panic/internal/%c3%b9tf8.(*Strùct).Pànic",
-			s:            "/gpremote/src/github.com/maruel/panicparse/cmd/panic/internal/ùtf8/ùtf8.go",
-			DirSrc:       pathJoin("ùtf8", "ùtf8.go"),
-			SrcName:      "ùtf8.go",
-			LocalSrcPath: "/gplocal/src/github.com/maruel/panicparse/cmd/panic/internal/ùtf8/ùtf8.go",
-			RelSrcPath:   "github.com/maruel/panicparse/cmd/panic/internal/ùtf8/ùtf8.go",
+			s:            "/gpremote/src/github.com/maruel/panicparse/cmd/panic/internal/ùtf8/utf8.go",
+			DirSrc:       pathJoin("ùtf8", "utf8.go"),
+			SrcName:      "utf8.go",
+			LocalSrcPath: "/gplocal/src/github.com/maruel/panicparse/cmd/panic/internal/ùtf8/utf8.go",
+			RelSrcPath:   "github.com/maruel/panicparse/cmd/panic/internal/ùtf8/utf8.go",
 			ImportPath:   "github.com/maruel/panicparse/cmd/panic/internal/ùtf8",
 			Location:     GOPATH,
 		},