Duplicate field name in struct literal is not reported

[horkhe]

• Plugin version (or commit hash): 0.12.1811
• IntelliJ IDEA 2016.2.3
• Build #IU-162.1812.17, built on August 30, 2016
• JRE: 1.8.0_112-release-b287 x86_64
• JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
• OS: Max OS X 10.11.6

The following code contains a syntax error, but it is not highlighted in the editor:

type Foo struct {
    Bar int
}

var foo = Foo{
    Bar: 0,
    Bar: 1, // Should be error: duplicate field name in struct literal: Bar
}