[ConstraintSystem] Don't increase SK_Fix score when looking through holes

`SK_Fix` was used to indicate that solver has encountered a hole
along the current path but since there is `SK_Hole` now, increasing
`SK_Fix` no longer makes sense.

Author: xedin

lib/Sema/CSSimplify.cpp

@@ -5073,7 +5073,6 @@ ConstraintSystem::SolutionKind ConstraintSystem::simplifyConformsToConstraint(
     // func foo<T: BinaryInteger>(_: T) {}
     // foo(Foo.bar) <- if `Foo` doesn't have `bar` there is
     //                 no reason to complain about missing conformance.
-    increaseScore(SK_Fix);
     return SolutionKind::Solved;
   }
 
@@ -6466,7 +6465,6 @@ ConstraintSystem::SolutionKind ConstraintSystem::simplifyMemberConstraint(
                baseObjTy->isHole()) {
       // If base type is a "hole" there is no reason to record any
       // more "member not found" fixes for chained member references.
-      increaseScore(SK_Fix);
       markMemberTypeAsPotentialHole(memberTy);
       return SolutionKind::Solved;
     }

test/Constraints/rdar44770297.swift

@@ -4,11 +4,11 @@ protocol P {
   associatedtype A
 }
 
-func foo<T: P>(_: () throws -> T) -> T.A? {
+func foo<T: P>(_: () throws -> T) -> T.A? { // expected-note {{where 'T' = 'Never'}}
   fatalError()
 }
 
-// TODO(diagnostics): This expression is truly ambiguous because there is no conformance between `Never` and `P`
-// which means no associated type `A` and `nil` can't be an argument to any overload of `&` so we end
-// up generating at least 3 fixes per overload of `&`. But we could at least point to where the problems are.
-let _ = foo() {fatalError()} & nil // expected-error {{type of expression is ambiguous without more context}}
+let _ = foo() {fatalError()} & nil // expected-error {{global function 'foo' requires that 'Never' conform to 'P'}}
+// expected-error@-1 {{value of optional type 'Never.A?' must be unwrapped to a value of type 'Never.A'}}
+// expected-note@-2 {{force-unwrap}}
+// expected-note@-3 {{coalesce using '??'}}

test/decl/enum/enumtest.swift

@@ -36,8 +36,7 @@ func test1a() -> unionSearchFlags {
 
 func test1b(_ b : Bool) {
   _ = 123
-  _ = .description == 1 // expected-error {{instance member 'description' cannot be used on type 'Int'}}
-  // expected-error@-1 {{member 'description' in 'Int' produces result of type 'String', but context expects 'Int'}}
+  _ = .description == 1 // expected-error {{cannot infer contextual base in reference to member 'description'}}
 }
 
 enum MaybeInt {