[clang][nfc] Update some documentation referring to old clang flags

-cfg-dump and -cfg-view were removed long ago. The rest are gone, but
I'm opting not to remove these lines without finding a replacement.

clang/lib/StaticAnalyzer/README.txt

@@ -119,15 +119,17 @@ simulation results.
 
 Of course, viewing the CFG (Control-Flow Graph) is also useful:
 
-$ clang -cc1 -help | grep cfg
- -cfg-add-implicit-dtors Add C++ implicit destructors to CFGs for all analyses
- -cfg-add-initializers   Add C++ initializers to CFGs for all analyses
- -cfg-dump               Display Control-Flow Graphs
- -cfg-view               View Control-Flow Graphs using GraphViz
- -unoptimized-cfg        Generate unoptimized CFGs for all analyses
-
--cfg-dump dumps a textual representation of the CFG to the console,
-and -cfg-view creates a GraphViz representation.
+$ clang -cc1 -analyzer-checker-help-developer
+
+ -analyzer-checker=debug.DumpCFG   Display Control-Flow Graphs
+ -analyzer-checker=debug.ViewCFG   View Control-Flow Graphs using GraphViz
+(outdated below?)
+ -cfg-add-implicit-dtors           Add C++ implicit destructors to CFGs for all analyses
+ -cfg-add-initializers             Add C++ initializers to CFGs for all analyses
+ -unoptimized-cfg                  Generate unoptimized CFGs for all analyses
+
+debug.DumpCFG dumps a textual representation of the CFG to the console, and
+debug.ViewCFG creates a GraphViz representation.
 
 = References =