[RequirementMachine] Record the sugared 'Self' type parameter when

initializing a RequirementMachine for a written protocol signature.

These generic parameters are used for re-sugaring when computing a
type from a term, so if the recorded 'Self' parameter is canonicalized,
it shows up in diagnostics as 'tau_0_0'.

Author: hborla

lib/AST/RequirementMachine/RequirementMachine.cpp

@@ -366,7 +366,7 @@ RequirementMachine::initWithProtocolWrittenRequirements(
 
   // For RequirementMachine::verify() when called by generic signature queries;
   // We have a single valid generic parameter at depth 0, index 0.
-  Params.push_back(component[0]->getSelfInterfaceType()->getCanonicalType());
+  Params.push_back(component[0]->getSelfInterfaceType());
 
   if (Dump) {
     llvm::dbgs() << "Adding protocols";

test/Generics/concrete_conflict.swift

@@ -1,5 +1,4 @@
-// RUN: %target-typecheck-verify-swift
-// RUN: %target-swift-frontend -typecheck %s -debug-generic-signatures -requirement-machine-protocol-signatures=on -requirement-machine-inferred-signatures=on 2>&1 | %FileCheck %s
+// RUN: %target-swift-frontend -typecheck -verify %s -debug-generic-signatures -requirement-machine-protocol-signatures=on -requirement-machine-inferred-signatures=on 2>&1 | %FileCheck %s
 
 protocol P1 {
   associatedtype T where T == Int
@@ -25,11 +24,11 @@ protocol P3 {
 // CHECK-LABEL: .P4@
 // CHECK-LABEL: Requirement signature: <Self where Self.[P4]T : P1, Self.[P4]T : P2, Self.[P4]T : P3>
 
+// expected-error@+3{{no type for 'Self.T.T' can satisfy both 'Self.T.T == Int' and 'Self.T.T == String'}}
+// expected-error@+2{{no type for 'Self.T.T' can satisfy both 'Self.T.T == Int' and 'Self.T.T == Float'}}
+// expected-error@+1{{no type for 'Self.T.T' can satisfy both 'Self.T.T == String' and 'Self.T.T == Float'}}
 protocol P4 {
   associatedtype T : P1 & P2 & P3
-  // expected-note@-1 2{{same-type constraint 'Self.T.T' == 'Int' implied here}}
-  // expected-error@-2 {{'Self.T.T' cannot be equal to both 'String' and 'Int'}}
-  // expected-error@-3 {{'Self.T.T' cannot be equal to both 'Float' and 'Int'}}
 }
 
 class Class<T> {}
@@ -38,5 +37,5 @@ extension Class where T == Bool {
   // CHECK-LABEL: .badRequirement()@
   // CHECK-NEXT: <T>
   func badRequirement() where T == Int { }
-  // expected-error@-1 {{generic parameter 'T' cannot be equal to both 'Int' and 'Bool'}}
-}
+  // expected-error@-1 {{no type for 'T' can satisfy both 'T == Bool' and 'T == Int'}}
+}

test/Generics/protocol_self_concrete_error.swift

@@ -7,4 +7,5 @@
 
 struct S {}
 
+// expected-error@+1 {{no type for 'Self' can satisfy both 'Self : P' and 'Self == S'}}
 protocol P where Self == S {}