class fields: added tests for privatename production

# Conflicts:
#	src/class-fields/default/cls-decl-after-same-line-async-gen.template
#	src/class-fields/default/cls-decl-after-same-line-async-method.template
#	src/class-fields/default/cls-decl-after-same-line-gen.template
#	src/class-fields/default/cls-decl-after-same-line-method.template
#	src/class-fields/default/cls-decl-after-same-line-static-async-gen.template
#	src/class-fields/default/cls-decl-after-same-line-static-async-method.template
#	src/class-fields/default/cls-decl-after-same-line-static-gen.template
#	src/class-fields/default/cls-decl-after-same-line-static-method.template
#	src/class-fields/default/cls-decl-multiple-definitions.template
#	src/class-fields/default/cls-decl-multiple-stacked-definitions.template
#	src/class-fields/default/cls-decl-new-no-sc-line-method.template
#	src/class-fields/default/cls-decl-new-sc-line-generator.template
#	src/class-fields/default/cls-decl-new-sc-line-method.template
#	src/class-fields/default/cls-decl-regular-definitions.template
#	src/class-fields/default/cls-decl-same-line-generator.template
#	src/class-fields/default/cls-decl-same-line-method.template
#	src/class-fields/default/cls-decl-wrapped-in-sc.template
#	src/class-fields/default/cls-expr-after-same-line-async-gen.template
#	src/class-fields/default/cls-expr-after-same-line-async-method.template
#	src/class-fields/default/cls-expr-after-same-line-gen.template
#	src/class-fields/default/cls-expr-after-same-line-method.template
#	src/class-fields/default/cls-expr-after-same-line-static-async-gen.template
#	src/class-fields/default/cls-expr-after-same-line-static-async-method.template
#	src/class-fields/default/cls-expr-after-same-line-static-gen.template
#	src/class-fields/default/cls-expr-after-same-line-static-method.template
#	src/class-fields/default/cls-expr-multiple-definitions.template
#	src/class-fields/default/cls-expr-multiple-stacked-definitions.template
#	src/class-fields/default/cls-expr-new-no-sc-line-method.template
#	src/class-fields/default/cls-expr-new-sc-line-generator.template
#	src/class-fields/default/cls-expr-new-sc-line-method.template
#	src/class-fields/default/cls-expr-regular-definitions.template
#	src/class-fields/default/cls-expr-same-line-generator.template
#	src/class-fields/default/cls-expr-same-line-method.template
#	src/class-fields/default/cls-expr-wrapped-in-sc.template
#	src/class-fields/private-names.case