Fix #1792: Allow newline in front of { when supporting procedure syntax.

Author: odersky

compiler/src/dotty/tools/dotc/parsing/Parsers.scala

@@ -1897,6 +1897,7 @@ object Parsers {
       if (in.token == THIS) {
         in.nextToken()
         val vparamss = paramClauses(nme.CONSTRUCTOR)
+        if (in.isScala2Mode) newLineOptWhenFollowedBy(LBRACE)
         val rhs = {
           if (!(in.token == LBRACE && scala2ProcedureSyntax(""))) accept(EQUALS)
           atPos(in.offset) { constrExpr() }
@@ -1908,6 +1909,7 @@ object Parsers {
         val tparams = typeParamClauseOpt(ParamOwner.Def)
         val vparamss = paramClauses(name)
         var tpt = fromWithinReturnType(typedOpt())
+        if (in.isScala2Mode) newLineOptWhenFollowedBy(LBRACE)
         val rhs =
           if (in.token == EQUALS) {
             in.nextToken()

tests/pos-scala2/i1792.scala

@@ -0,0 +1,8 @@
+object Test {
+
+def foo(x: Int)
+{
+  x
+}
+
+}