Deprecate SelectMode.Single and backport evalOrThrow API

[lolgab]

No description provided.

[lefou]

This supersedes #2554, I guess?

[lefou]

Looks good to me.

[lefou]

This PR breaks binary compatibility.

[1527/1698] main.core.mimaReportBinaryIssues 
Scanning binary compatibility in /home/lefou/work/opensource/mill-0.10.x/out/main/core/compile.dest/classes ...
Found 1 issue when checking against com.lihaoyi:mill-main-core_2.13:0.10.0
 * static method evalOrThrow(mill.eval.Evaluator,scala.Function1)mill.eval.Evaluator#EvalOrThrow in class mill.eval.Evaluator does not have a correspondent in current version
   filter with: ProblemFilter.exclude[DirectMissingMethodProblem]("mill.eval.Evaluator.evalOrThrow")
Found 1 issue when checking against com.lihaoyi:mill-main-core_2.13:0.10.1
 * static method evalOrThrow(mill.eval.Evaluator,scala.Function1)mill.eval.Evaluator#EvalOrThrow in class mill.eval.Evaluator does not have a correspondent in current version
   filter with: ProblemFilter.exclude[DirectMissingMethodProblem]("mill.eval.Evaluator.evalOrThrow")
Found 1 issue when checking against com.lihaoyi:mill-main-core_2.13:0.10.2
 * static method evalOrThrow(mill.eval.Evaluator,scala.Function1)mill.eval.Evaluator#EvalOrThrow in class mill.eval.Evaluator does not have a correspondent in current version
   filter with: ProblemFilter.exclude[DirectMissingMethodProblem]("mill.eval.Evaluator.evalOrThrow")
Found 1 issue when checking against com.lihaoyi:mill-main-core_2.13:0.10.3
 * static method evalOrThrow(mill.eval.Evaluator,scala.Function1)mill.eval.Evaluator#EvalOrThrow in class mill.eval.Evaluator does not have a correspondent in current version
   filter with: ProblemFilter.exclude[DirectMissingMethodProblem]("mill.eval.Evaluator.evalOrThrow")
Found 1 issue when checking against com.lihaoyi:mill-main-core_2.13:0.10.4
 * static method evalOrThrow(mill.eval.Evaluator,scala.Function1)mill.eval.Evaluator#EvalOrThrow in class mill.eval.Evaluator does not have a correspondent in current version
   filter with: ProblemFilter.exclude[DirectMissingMethodProblem]("mill.eval.Evaluator.evalOrThrow")
Found 1 issue when checking against com.lihaoyi:mill-main-core_2.13:0.10.5
 * static method evalOrThrow(mill.eval.Evaluator,scala.Function1)mill.eval.Evaluator#EvalOrThrow in class mill.eval.Evaluator does not have a correspondent in current version
   filter with: ProblemFilter.exclude[DirectMissingMethodProblem]("mill.eval.Evaluator.evalOrThrow")
Found 1 issue when checking against com.lihaoyi:mill-main-core_2.13:0.10.6
 * static method evalOrThrow(mill.eval.Evaluator,scala.Function1)mill.eval.Evaluator#EvalOrThrow in class mill.eval.Evaluator does not have a correspondent in current version
   filter with: ProblemFilter.exclude[DirectMissingMethodProblem]("mill.eval.Evaluator.evalOrThrow")
Found 1 issue when checking against com.lihaoyi:mill-main-core_2.13:0.10.7
 * static method evalOrThrow(mill.eval.Evaluator,scala.Function1)mill.eval.Evaluator#EvalOrThrow in class mill.eval.Evaluator does not have a correspondent in current version
   filter with: ProblemFilter.exclude[DirectMissingMethodProblem]("mill.eval.Evaluator.evalOrThrow")
Found 1 issue when checking against com.lihaoyi:mill-main-core_2.13:0.10.8
 * static method evalOrThrow(mill.eval.Evaluator,scala.Function1)mill.eval.Evaluator#EvalOrThrow in class mill.eval.Evaluator does not have a correspondent in current version
   filter with: ProblemFilter.exclude[DirectMissingMethodProblem]("mill.eval.Evaluator.evalOrThrow")
Found 1 issue when checking against com.lihaoyi:mill-main-core_2.13:0.10.9
 * static method evalOrThrow(mill.eval.Evaluator,scala.Function1)mill.eval.Evaluator#EvalOrThrow in class mill.eval.Evaluator does not have a correspondent in current version
   filter with: ProblemFilter.exclude[DirectMissingMethodProblem]("mill.eval.Evaluator.evalOrThrow")
Found 1 issue when checking against com.lihaoyi:mill-main-core_2.13:0.10.10
 * static method evalOrThrow(mill.eval.Evaluator,scala.Function1)mill.eval.Evaluator#EvalOrThrow in class mill.eval.Evaluator does not have a correspondent in current version
   filter with: ProblemFilter.exclude[DirectMissingMethodProblem]("mill.eval.Evaluator.evalOrThrow")
Found 1 issue when checking against com.lihaoyi:mill-main-core_2.13:0.10.11
 * static method evalOrThrow(mill.eval.Evaluator,scala.Function1)mill.eval.Evaluator#EvalOrThrow in class mill.eval.Evaluator does not have a correspondent in current version
   filter with: ProblemFilter.exclude[DirectMissingMethodProblem]("mill.eval.Evaluator.evalOrThrow")
[1527/1698] main.core.mimaReportBinaryIssues failed

I guess this is because you can't have the same methods defined as static and non-static.

@lolgab Should we revert this?

[lefou]

But if I look closer, the signature of the class's evalOrThrow and the object's evalOrThrow aren't the same. I have no idea, why MiMa thinks the method is missing.

[lefou]

The actual class file seen to contain boths methods, so this is probably a false positive?

> javap out/main/core/compile.dest/classes/mill/eval/Evaluator.class 
Compiled from "Evaluator.scala"
public class mill.eval.Evaluator implements scala.Product,java.io.Serializable {
  ...
  public mill.eval.Evaluator$EvalOrThrow evalOrThrow(scala.Function1<mill.eval.Evaluator$Results, java.lang.Throwable>);
  ...
  public static final java.lang.Exception $anonfun$evalOrThrow$default$1$1(mill.eval.Evaluator$Results);  
  ...
}