compile-time error if a redirecting constructor includes a body

[DartBot]

This issue was originally filed by zundel@google.com

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dartc fails co19 test Language/07_Classes/07_Classes_A02_t06.dart

class A {
  A(): this.B() {} // body not allowed
  A.B() {}
}

[kasperl]

Removed Area-Compiler label.
Added Area-Analyzer label.

[danrubel]

Added this to the M1 milestone.

[DartBot]

This comment was originally written by zundel@google.com

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Set owner to zundel@google.com.
Added Accepted label.

[DartBot]

This comment was originally written by zundel@google.com

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https://chromiumcodereview.appspot.com/10635004

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Added Started label.

[DartBot]

This comment was originally written by zundel@google.com

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r8982

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Added Fixed label.