cmMakefile: Consify custom command API.

Source/cmCustomCommand.cxx

@@ -64,7 +64,7 @@ cmCustomCommand& cmCustomCommand::operator=(cmCustomCommand const& r)
 }
 
 //----------------------------------------------------------------------------
-cmCustomCommand::cmCustomCommand(cmMakefile* mf,
+cmCustomCommand::cmCustomCommand(cmMakefile const* mf,
                                  const std::vector<std::string>& outputs,
                                  const std::vector<std::string>& depends,
                                  const cmCustomCommandLines& commandLines,

Source/cmCustomCommand.h

@@ -30,7 +30,7 @@ public:
   cmCustomCommand& operator=(cmCustomCommand const& r);
 
   /** Main constructor specifies all information for the command.  */
-  cmCustomCommand(cmMakefile* mf,
+  cmCustomCommand(cmMakefile const* mf,
                   const std::vector<std::string>& outputs,
                   const std::vector<std::string>& depends,
                   const cmCustomCommandLines& commandLines,

Source/cmMakefile.cxx

@@ -884,7 +884,7 @@ cmMakefile::AddCustomCommandToTarget(const char* target,
                                      cmTarget::CustomCommandType type,
                                      const char* comment,
                                      const char* workingDir,
-                                     bool escapeOldStyle)
+                                     bool escapeOldStyle) const
 {
   // Find the target to which to add the custom command.
   cmTargets::iterator ti = this->Targets.find(target);

Source/cmMakefile.h

@@ -173,7 +173,7 @@ public:
                                 const cmCustomCommandLines& commandLines,
                                 cmTarget::CustomCommandType type,
                                 const char* comment, const char* workingDir,
-                                bool escapeOldStyle = true);
+                                bool escapeOldStyle = true) const;
   cmSourceFile* AddCustomCommandToOutput(
     const std::vector<std::string>& outputs,
     const std::vector<std::string>& depends,