FULL PRODUCT VERSION :
java version "10-ea"
Java(TM) SE Runtime Environment (build 10-ea+32)
Java HotSpot(TM) 64-Bit Server VM (build 10-ea+32, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 10.0.15063]

A DESCRIPTION OF THE PROBLEM :
When assigning a void expression to a "var" declaration, the compiler crashes

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Compile the example file below

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The compiler emits a syntax error
ACTUAL -
The compiler crashes

ERROR MESSAGES/STACK TRACES THAT OCCUR :

Output from compiling below code
java.lang.AssertionError
        at jdk.compiler/com.sun.tools.javac.jvm.Items$Item.load(Items.java:206)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitVarDef(Gen.java:1015)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCVariableDecl.accept(JCTree.java:956)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genDef(Gen.java:595)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStat(Gen.java:630)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStat(Gen.java:616)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStats(Gen.java:667)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitBlock(Gen.java:1029)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:1020)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genDef(Gen.java:595)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStat(Gen.java:630)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genMethod(Gen.java:901)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitMethodDef(Gen.java:864)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:866)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genDef(Gen.java:595)
        at jdk.compiler/com.sun.tools.javac.jvm.Gen.genClass(Gen.java:2182)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.genCode(JavaCompiler.java:747)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.generate(JavaCompiler.java:1626)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.generate(JavaCompiler.java:1594)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:964)
        at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:306)
        at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:165)
        at jdk.compiler/com.sun.tools.javac.Main.compile(Main.java:57)
        at jdk.compiler/com.sun.tools.javac.Main.main(Main.java:43)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
class Test {
    void m() {
        var x = n();
    }

    void n() {

    }
}
---------- END SOURCE ----------