GSB: inline some trivial methods

This inlines the comparators since GCC 7 objects to the definition
(which is probably due to scoping).  However, these methods are
templates, which must be visible to the consumers, and should therefore
be in the header.  Given the size, it seems reasonable to just inline
them.

Author: compnerd

include/swift/AST/GenericSignatureBuilder.h

@@ -1687,6 +1687,21 @@ class GenericSignatureBuilder::PotentialArchetype {
   friend class GenericSignatureBuilder;
 };
 
+template <typename C>
+bool GenericSignatureBuilder::Constraint<C>::isSubjectEqualTo(Type T) const {
+  return getSubjectDependentType({ })->isEqual(T);
+}
+
+template <typename T>
+bool GenericSignatureBuilder::Constraint<T>::isSubjectEqualTo(const GenericSignatureBuilder::PotentialArchetype *PA) const {
+  return getSubjectDependentType({ })->isEqual(PA->getDependentType({ }));
+}
+
+template <typename T>
+bool GenericSignatureBuilder::Constraint<T>::hasSameSubjectAs(const GenericSignatureBuilder::Constraint<T> &C) const {
+  return getSubjectDependentType({ })->isEqual(C.getSubjectDependentType({ }));
+}
+
 /// Describes a requirement whose processing has been delayed for some reason.
 class GenericSignatureBuilder::DelayedRequirement {
 public:

lib/AST/GenericSignatureBuilder.cpp

@@ -1712,22 +1712,6 @@ bool EquivalenceClass::recordConformanceConstraint(
   return inserted;
 }
 
-template<typename T>
-bool Constraint<T>::isSubjectEqualTo(Type type) const {
-  return getSubjectDependentType({ })->isEqual(type);
-}
-
-template<typename T>
-bool Constraint<T>::isSubjectEqualTo(const PotentialArchetype *pa) const {
-  return getSubjectDependentType({ })->isEqual(pa->getDependentType({ }));
-}
-
-template<typename T>
-bool Constraint<T>::hasSameSubjectAs(const Constraint<T> &other) const {
-  return getSubjectDependentType({ })
-    ->isEqual(other.getSubjectDependentType({ }));
-}
-
 Optional<ConcreteConstraint>
 EquivalenceClass::findAnyConcreteConstraintAsWritten(Type preferredType) const {
   // If we don't have a concrete type, there's no source.