JsChecker NullPointerException when there is a function redefinition

If a javascript class has a function redefined, the JsChecker will crash with the NullPointerException. This is critical because in react, we had to use this.toggleButton = this.toggleButton.bind(this); And this is considered as function redefinition.

ERROR: /home/liangzou/gitreview/XXX/javascript/common/react/components/BUILD:18:1: Checking 3 JS files in //javascript/common/react/components:search failed (Exit 1).
ERROR: Program threw uncaught exception with args: JsChecker --label //javascript/common/react/components:search --output bazel-out/local-fastbuild/bin/javascript/common/react/components/search.pbtxt --output_errors bazel-out/local-fastbuild/bin/javascript/common/react/components/search-stderr.txt --output_ijs_file bazel-out/local-fastbuild/bin/javascript/common/react/components/search.i.js --convention CLOSURE --src javascript/common/react/components/search.js --src javascript/common/react/components/search_form.js --src javascript/common/react/components/search_details.js --dep bazel-out/local-fastbuild/bin/external/io_bazel_rules_closure/closure/library/library.pbtxt --dep bazel-out/local-fastbuild/bin/javascript/third_party/react/react_with_addons_lib.pbtxt --dep bazel-out/local-fastbuild/bin/javascript/common/services/query_class_lib.pbtxt --dep bazel-out/local-fastbuild/bin/javascript/third_party/react/react_material_ui_lib.pbtxt
java.lang.NullPointerException
at com.google.javascript.jscomp.ijs.ConvertToTypedInterface$SimplifyDeclarations.shouldRemove(ConvertToTypedInterface.java:521)
at com.google.javascript.jscomp.ijs.ConvertToTypedInterface$SimplifyDeclarations.processDeclaration(ConvertToTypedInterface.java:443)
at com.google.javascript.jscomp.ijs.ConvertToTypedInterface$SimplifyDeclarations.simplifyAll(ConvertToTypedInterface.java:437)
at com.google.javascript.jscomp.ijs.ConvertToTypedInterface.processFile(ConvertToTypedInterface.java:96)
at com.google.javascript.jscomp.ijs.ConvertToTypedInterface.process(ConvertToTypedInterface.java:87)
at com.google.javascript.jscomp.PhaseOptimizer$NamedPass.process(PhaseOptimizer.java:300)
at com.google.javascript.jscomp.PhaseOptimizer.process(PhaseOptimizer.java:227)
at com.google.javascript.jscomp.Compiler.check(Compiler.java:1067)
at com.google.javascript.jscomp.Compiler.performChecksAndTranspilation(Compiler.java:866)
at com.google.javascript.jscomp.Compiler.access$000(Compiler.java:102)
at com.google.javascript.jscomp.Compiler$2.call(Compiler.java:800)
at com.google.javascript.jscomp.Compiler$2.call(Compiler.java:797)
at com.google.javascript.jscomp.CompilerExecutor.runInCompilerThread(CompilerExecutor.java:128)
at com.google.javascript.jscomp.Compiler.runInCompilerThread(Compiler.java:854)
at com.google.javascript.jscomp.Compiler.stage1Passes(Compiler.java:796)
at com.google.javascript.jscomp.Compiler.compile(Compiler.java:713)
at com.google.javascript.jscomp.JsChecker.run(JsChecker.java:249)
at com.google.javascript.jscomp.JsChecker.access$300(JsChecker.java:63)
at com.google.javascript.jscomp.JsChecker$Program.apply(JsChecker.java:341)
at io.bazel.rules.closure.worker.LegacyAspect.run(LegacyAspect.java:38)
at io.bazel.rules.closure.ClosureWorker.run(ClosureWorker.java:69)
at io.bazel.rules.closure.worker.PersistentWorker.runProgram(PersistentWorker.java:109)
at io.bazel.rules.closure.worker.PersistentWorker.runAsPersistentWorker(PersistentWorker.java:144)
at io.bazel.rules.closure.worker.PersistentWorker.run(PersistentWorker.java:84)
at io.bazel.rules.closure.ClosureWorker.main(ClosureWorker.java:111)

Start in com.google.javascript.jscomp.ijs.ConvertToTypedInterface.java, especially SimplifyDeclarations.shouldRemove at line 521 and processDeclaration around line 443. Reproduce with the JsChecker command and JavaScript class pattern described in the report. Done means JsChecker handles the function redefinition without an uncaught NullPointerException.

Written by the indexing model from the issue text.