TargetMachine: document unnamed bool argument

Its meaning was slightly mysterious without looking at
subclasses.

llvm-svn: 145705

Author: nobled

llvm/include/llvm/Target/TargetMachine.h

@@ -249,7 +249,7 @@ class TargetMachine {
   virtual bool addPassesToEmitFile(PassManagerBase &,
                                    formatted_raw_ostream &,
                                    CodeGenFileType,
-                                   bool = true) {
+                                   bool /*DisableVerify*/ = true) {
     return true;
   }
 
@@ -261,7 +261,7 @@ class TargetMachine {
   ///
   virtual bool addPassesToEmitMachineCode(PassManagerBase &,
                                           JITCodeEmitter &,
-                                          bool = true) {
+                                          bool /*DisableVerify*/ = true) {
     return true;
   }
 
@@ -273,7 +273,7 @@ class TargetMachine {
   virtual bool addPassesToEmitMC(PassManagerBase &,
                                  MCContext *&,
                                  raw_ostream &,
-                                 bool = true) {
+                                 bool /*DisableVerify*/ = true) {
     return true;
   }
 };