Parser: recover on missing interface members

Author: auduchinok

src/Compiler/FSComp.txt

@@ -1828,3 +1828,4 @@ featureErrorOnMissingSignatureAttribute,"error (rather than warning) when an enf
 featureNotNullIfNotNull,"honor the 'NotNullIfNotNull' attribute on a method's return value"
 featureAccessProtectedBaseFieldFromClosure,"Access a protected base-class field from a closure inside a member"
 featureImprovedImpliedArgumentNamesPartTwo,"Improved implied argument names with partial application"
+3892,parsExpectingMember,"Expecting member"

src/Compiler/pars.fsy

@@ -2311,6 +2311,12 @@ opt_interfaceImplDefn:
 
   | WITH
      { let mWithKwd = rhs parseState 1
+       reportParseErrorAt mWithKwd (FSComp.SR.parsExpectingMember ())
+       Some(mWithKwd, [], mWithKwd) }
+
+  | OWITH recover
+     { let mWithKwd = rhs parseState 1
+       reportParseErrorAt mWithKwd (FSComp.SR.parsExpectingMember ())
        Some(mWithKwd, [], mWithKwd) }
 
   | /* EMPTY */