[IDE] Switch to using symbol names for reconstructing types

This is closer to what the debugger and USRs will look like, and
includes more context needed in some cases.

Author: benlangmuir

test/IDE/reconstruct_type_from_mangled_name.swift

@@ -81,6 +81,15 @@ struct MyGenStruct1<T, U: StringLiteralConvertible, V: Sequence> {
 // CHECK: reconstructed decl from usr for 'y' is 'let y: U'
   let z: V
 // CHECK: reconstructed decl from usr for 'z' is 'let z: V'
+
+  func test000() {
+    _ = x
+// CHECK: reconstructed type from usr for 'x' is 'T'
+    _ = y
+// CHECK: reconstructed type from usr for 'y' is 'U'
+    _ = z
+// CHECK: reconstructed type from usr for 'z' is 'V'
+  }
 }
 
 let genstruct1 = MyGenStruct1<Int, String, [Float]>(x: 1, y: "", z: [1.0])

tools/swift-ide-test/swift-ide-test.cpp

@@ -2389,10 +2389,10 @@ class TypeReconstructWalker : public SourceEntityWalker {
       return true;
     T = T->getRValueType();
     Mangle::Mangler Man(/* DWARFMangling */true);
-    Man.mangleType(T, 0);
+    Man.mangleTypeForDebugger(T, D->getDeclContext());
     std::string MangledName(Man.finalize());
     std::string Error;
-    Type ReconstructedType = getTypeFromMangledTypename(Ctx, MangledName,
+    Type ReconstructedType = getTypeFromMangledSymbolname(Ctx, MangledName,
                                                         Error);
     if (ReconstructedType) {
       Stream << "reconstructed type from usr for '" << Range.str() << "' is '";