Allow to suppress "inlined from" parts when printing trees

-Yshow-no-inline suppresses "inlined from" parts when printing trees. This is
useful when one has deeply inlined structures, as is the case when looking at `trace`ed code.

Author: odersky

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -87,6 +87,7 @@ class ScalaSettings extends Settings.SettingGroup {
   val YdisableFlatCpCaching  = BooleanSetting("-YdisableFlatCpCaching", "Do not cache flat classpath representation of classpath elements from jars across compiler instances.")
 
   val YnoImports = BooleanSetting("-Yno-imports", "Compile without importing scala.*, java.lang.*, or Predef.")
+  val YnoInline = BooleanSetting("-Yno-inline", "Suppress inlining.")
   val YnoGenericSig = BooleanSetting("-Yno-generic-signatures", "Suppress generation of generic signatures for Java.")
   val YnoPredef = BooleanSetting("-Yno-predef", "Compile without importing Predef.")
   val Yskip = PhasesSetting("-Yskip", "Skip")
@@ -126,7 +127,7 @@ class ScalaSettings extends Settings.SettingGroup {
   val YexplainLowlevel = BooleanSetting("-Yexplain-lowlevel", "When explaining type errors, show types at a lower level.")
   val YnoDoubleBindings = BooleanSetting("-Yno-double-bindings", "Assert no namedtype is bound twice (should be enabled only if program is error-free).")
   val YshowVarBounds = BooleanSetting("-Yshow-var-bounds", "Print type variables with their bounds")
-  val YnoInline = BooleanSetting("-Yno-inline", "Suppress inlining.")
+  val YshowNoInline = BooleanSetting("-Yshow-no-inline", "Show inlined code without the 'inlined from' info")
 
   /** Linker specific flags */
   val optimise = BooleanSetting("-optimise", "Generates faster bytecode by applying local optimisations to the .program") withAbbreviation "-optimize"

compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala

@@ -359,7 +359,7 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
       case SeqLiteral(elems, elemtpt) =>
         "[" ~ toTextGlobal(elems, ",") ~ " : " ~ toText(elemtpt) ~ "]"
       case tree @ Inlined(call, bindings, body) =>
-        (("/* inlined from " ~ toText(call) ~ "*/ ") provided !homogenizedView) ~
+        (("/* inlined from " ~ toText(call) ~ "*/ ") provided !homogenizedView && !ctx.settings.YshowNoInline.value) ~
         blockText(bindings :+ body)
       case tpt: untpd.DerivedTypeTree =>
         "<derived typetree watching " ~ summarized(toText(tpt.watched)) ~ ">"