Swift SIL: add some APIs to Location

* `hasValidLineNumber`
* `isAutoGenerated`
* `isDebugSteppable`

Author: eeckstein

SwiftCompilerSources/Sources/SIL/Location.swift

@@ -25,6 +25,11 @@ public struct Location: Equatable, CustomStringConvertible {
     Location(bridged: SILLocation_getAutogeneratedLocation(bridged))
   }
 
+  public var hasValidLineNumber: Bool { bridged.hasValidLineNumber() }
+  public var isAutoGenerated: Bool { bridged.isAutoGenerated() }
+
+  public var isDebugSteppable: Bool { hasValidLineNumber && !isAutoGenerated }
+
   public static func ==(lhs: Location, rhs: Location) -> Bool {
     SILLocation_equal(lhs.bridged, rhs.bridged)
   }

include/swift/SIL/SILLocation.h

@@ -307,6 +307,14 @@ class SILLocation {
   }
   explicit operator bool() const { return !isNull(); }
 
+  bool hasValidLineNumber() const {
+    if (isNull())
+      return false;
+    if (isFilenameAndLocation() && getFilenameAndLocation()->line == 0)
+      return false;
+    return true;
+  }
+
   /// Return true if this location is backed by an AST node.
   bool isASTNode() const {
     switch (getStorageKind()) {
@@ -691,6 +699,8 @@ class SILDebugLocation {
       : debugScope(debugScope), location(location) {}
   SILLocation getLocation() const { return location; }
   const SILDebugScope *getScope() const { return debugScope; }
+  bool hasValidLineNumber() const { return location.hasValidLineNumber(); }
+  bool isAutoGenerated() const { return location.isAutoGenerated(); }
   operator bool() const { return bool(location) && debugScope; }
 };