[LLDB] Expose several methods in SBWatchpoint

This patch adds the following methods:

* `GetType()`
* `GetWatchValueKind()`
* `GetWatchSpec()`
* `IsWatchingReads()`
* `IsWatchingWrites()`

These mostly expose methods that `lldb_private::Watchpoint` already
had. Tests are included that exercise these new methods.

The motivation for exposing these are as follows:

* `GetType()` - With this information and the address from a watchpoint
  it is now possible to construct an SBValue from an SBWatchpoint.
  Previously this wasn't possible. The included test case illustrates
  doing this.
* `GetWatchValueKind()` - This allows the caller to determine whether the
  watchpoint is a variable watchpoint or an expression watchpoint. A new
  enum (`WatchpointValueKind`) has been introduced to represent the
  return values. Unfortunately the name `WatchpointKind` was already
  taken.
* `GetWatchSpec()` - This allows (at least for variable watchpoints)
  to use a sensible name for SBValues created from an SBWatchpoint.
* `IsWatchingReads()` - This allow checking if a watchpoint is
  monitoring read accesses.
* `IsWatchingWRites()` - This allow checking if a watchpoint is
  monitoring write accesses.

rdar://105606978

Reviewers: jingham, mib, bulbazord, jasonmolenda, JDevlieghere

Differential Revision: https://reviews.llvm.org/D144937

(cherry picked from commit 55a363f)

Author: delcypher

lldb/bindings/interface/SBWatchpointDocstrings.i

@@ -19,3 +19,30 @@ watchpoints of the target."
 %feature("docstring", "
     The watchpoint stops only if the condition expression evaluates to true."
 ) lldb::SBWatchpoint::SetCondition;
+
+%feature("docstring", "
+    Returns the type recorded when the watchpoint was created. For variable
+    watchpoints it is the type of the watched variable. For expression
+    watchpoints it is the type of the provided expression."
+) lldb::SBWatchpoint::GetType;
+
+%feature("docstring", "
+    Returns the kind of value that was watched when the watchpoint was created.
+    Returns one of the following eWatchPointValueKindVariable,
+    eWatchPointValueKindExpression, eWatchPointValueKindInvalid.
+    "
+) lldb::SBWatchpoint::GetWatchValueKind;
+
+%feature("docstring", "
+    Get the spec for the watchpoint. For variable watchpoints this is the name
+    of the variable. For expression watchpoints it is empty
+    (may change in the future)."
+) lldb::SBWatchpoint::GetWatchSpec;
+
+%feature("docstring", "
+    Returns true if the watchpoint is watching reads. Returns false otherwise."
+) lldb::SBWatchpoint::IsWatchingReads;
+
+%feature("docstring", "
+    Returns true if the watchpoint is watching writes. Returns false otherwise."
+) lldb::SBWatchpoint::IsWatchingWrites;