C++: Change note and precision for DeadCodeGoto.ql

Author: Robert Marsh

change-notes/1.19/analysis-cpp.md

@@ -9,6 +9,7 @@
 | Cast between HRESULT and a Boolean type (`cpp/hresult-boolean-conversion`) | external/cwe/cwe-253 | Finds logic errors caused by mistakenly treating the Windows `HRESULT` type as a Boolean instead of testing it with the appropriate macros. Enabled by default. |
 | Setting a DACL to `NULL` in a `SECURITY_DESCRIPTOR` (`cpp/unsafe-dacl-security-descriptor`) | external/cwe/cwe-732 | This query finds code that creates world-writable objects on Windows by setting their DACL to `NULL`. Enabled by default. |
 | Cast from char* to wchar_t* | security, external/cwe/cwe-704 | Detects potentially dangerous casts from char* to wchar_t*.  Enabled by default on LGTM. |
+| Dead code due to goto or break statement (`cpp/dead-code-goto`) | maintainability, external/cwe/cwe-561 | Detects dead code following a goto or break statement. Enabled by default on LGTM. |
 
 ## Changes to existing queries
 

cpp/ql/src/Critical/DeadCodeGoto.ql

@@ -3,6 +3,7 @@
  * @description A goto or break statement is followed by unreachable code. 
  * @kind problem
  * @problem.severity warning
+ * @precision high
  * @id cpp/dead-code-goto
  * @tags maintainability
  *       external/cwe/cwe-561