Adding tests for coercion fix and fixing test/expr/cast/ tests

Author: LucianoPAlmeida

lib/Sema/CSSimplify.cpp

@@ -2807,12 +2807,17 @@ ConstraintSystem::matchTypes(Type type1, Type type2, ConstraintKind kind,
 
   // If the types are obviously equivalent, we're done.
   if (desugar1->isEqual(desugar2)) {
+    auto locatorPtr = locator.getBaseLocator();
     if (kind >= ConstraintKind::Conversion &&
-        locator.getBaseLocator()->
+        locatorPtr->
           isLastElement(ConstraintLocator::PathElementKind::ExplicityTypeCoercion)) {
-      if (!hasFixFor(locator.getBaseLocator())) {
+      if (!llvm::any_of(getFixes(), [&locatorPtr](const ConstraintFix *fix) -> bool {
+        if (fix->getLocator() == locatorPtr)
+          return true;
+        return fix->getLocator()->getAnchor() == locatorPtr->getAnchor();
+      })) {
         auto *fix = RemoveUnecessaryCoercion::create(*this, type2,
-                                                     locator.getBaseLocator());
+                                                     locatorPtr);
         recordFix(fix);
       }
     }

test/expr/cast/array_downcast.swift

@@ -24,7 +24,7 @@ var ta = [t]
 
 va = ta
 
-var va2: ([V])? = va as [V]
+var va2: ([V])? = va as [V] // expected-warning {{casting expression to '[V]' doesn't change the type}} {{22-29=}}
 var v2: V = va2![0]
 
 var ua2: ([U])? = va as? [U]

test/expr/cast/as_coerce.swift

@@ -81,7 +81,7 @@ c3 as C4 // expected-error {{'C3' is not convertible to 'C4'; did you mean to us
 // <rdar://problem/19495142> Various incorrect diagnostics for explicit type conversions
 1 as Double as Float // expected-error{{cannot convert value of type 'Double' to type 'Float' in coercion}}
 1 as Int as String // expected-error{{cannot convert value of type 'Int' to type 'String' in coercion}}
-Double(1) as Double as String // expected-error{{cannot convert value of type 'Double' to type 'String' in coercion}}
+Double(1) as Double as String // expected-error{{cannot convert value of type 'Double' to type 'String' in coercion}} // expected-warning {{casting expression to 'Double' doesn't change the type}} {{11-21=}}
 ["awd"] as [Int] // expected-error{{cannot convert value of type 'String' to expected element type 'Int'}}
 ([1, 2, 1.0], 1) as ([String], Int)
 // expected-error@-1 2 {{cannot convert value of type 'Int' to expected element type 'String'}}
@@ -155,13 +155,13 @@ _ = "Hello" as String // Ok
 _ = 1 as Int64 // Ok
 _ = [] as Set<Int> // Ok
 
-class A {}
-class B: A {}
+class SR11295A {}
+class SR11295B: SR11295A {}
 
-var a = A()
-var b = B()
+var sr11295ap = SR11295A()
+var sr11295bc = SR11295B()
 
-var ba = b as A // Ok 
+_ = sr11295bc as SR11295A // Ok 
 
 _ = 1 as Double as Double // expected-warning {{casting expression to 'Double' doesn't change the type}} {{17-27=}}
 _ = Double(1) as Double // expected-warning {{casting expression to 'Double' doesn't change the type}} {{15-25=}}