Ignore method name when doing mcs -removeDup (dotnet#602)

Thus, methods with different names but otherwise are identical will
match and only one will be retained.

This improves both Checked and Release, and fixes the Release
build removeDup regression introduced in dotnet#548.

src/coreclr/src/ToolBox/superpmi/mcs/verbremovedup.cpp

@@ -26,7 +26,7 @@ bool unique(MethodContext* mc)
     mc->repCompileMethod(&newInfo, &newFlags);
 
     char* md5Buff = new char[MD5_HASH_BUFFER_SIZE];
-    mc->dumpMethodMD5HashToBuffer(md5Buff, MD5_HASH_BUFFER_SIZE);
+    mc->dumpMethodMD5HashToBuffer(md5Buff, MD5_HASH_BUFFER_SIZE, /* ignoreMethodName */ true);
 
     if (inFile->GetIndex(newInfo.ILCodeSize) == -1)
         inFile->Add(newInfo.ILCodeSize, new DenseLightWeightMap<char*>());

src/coreclr/src/ToolBox/superpmi/superpmi-shared/callutils.cpp

@@ -258,12 +258,14 @@ const char* CallUtils::GetMethodName(MethodContext* mc, CORINFO_METHOD_HANDLE me
 }
 
 // Originally from src/jit/eeinterface.cpp
-const char* CallUtils::GetMethodFullName(MethodContext* mc, CORINFO_METHOD_HANDLE hnd, CORINFO_SIG_INFO sig)
+// If `ignoreMethodName` is `true`, we construct the function signature with a dummy method name that will be the
+// same for all methods.
+const char* CallUtils::GetMethodFullName(MethodContext* mc, CORINFO_METHOD_HANDLE hnd, CORINFO_SIG_INFO sig, bool ignoreMethodName /* = false */)
 {
     const char* returnType = NULL;
 
-    const char* className;
-    const char* methodName = GetMethodName(mc, hnd, &className);
+    const char* className = ignoreMethodName ? "CLASS" : nullptr;
+    const char* methodName = ignoreMethodName ? "METHOD" : GetMethodName(mc, hnd, &className);
     if ((GetHelperNum(hnd) != CORINFO_HELP_UNDEF) || IsNativeMethod(hnd))
     {
         return methodName;

src/coreclr/src/ToolBox/superpmi/superpmi-shared/callutils.h

@@ -34,7 +34,7 @@ class CallUtils
     static bool IsNativeMethod(CORINFO_METHOD_HANDLE method);
     static CORINFO_METHOD_HANDLE GetMethodHandleForNative(CORINFO_METHOD_HANDLE method);
     static const char* GetMethodName(MethodContext* mc, CORINFO_METHOD_HANDLE method, const char** classNamePtr);
-    static const char* GetMethodFullName(MethodContext* mc, CORINFO_METHOD_HANDLE hnd, CORINFO_SIG_INFO sig);
+    static const char* GetMethodFullName(MethodContext* mc, CORINFO_METHOD_HANDLE hnd, CORINFO_SIG_INFO sig, bool ignoreMethodName = false);
 };
 
 #endif

src/coreclr/src/ToolBox/superpmi/superpmi-shared/methodcontext.cpp

@@ -6346,7 +6346,7 @@ const WCHAR* MethodContext::repGetStringConfigValue(const WCHAR* name)
     return value;
 }
 
-int MethodContext::dumpMethodIdentityInfoToBuffer(char* buff, int len)
+int MethodContext::dumpMethodIdentityInfoToBuffer(char* buff, int len, bool ignoreMethodName /* = false */)
 {
     char* obuff = buff;
 
@@ -6360,7 +6360,7 @@ int MethodContext::dumpMethodIdentityInfoToBuffer(char* buff, int len)
     repCompileMethod(&info, &flags);
 
     // Add the Method Signature
-    int t = sprintf_s(buff, len, "%s -- ", CallUtils::GetMethodFullName(this, info.ftn, info.args));
+    int t = sprintf_s(buff, len, "%s -- ", CallUtils::GetMethodFullName(this, info.ftn, info.args, ignoreMethodName));
     buff += t;
     len -= t;
 
@@ -6379,11 +6379,11 @@ int MethodContext::dumpMethodIdentityInfoToBuffer(char* buff, int len)
 
     return (int)(buff - obuff);
 }
-int MethodContext::dumpMethodMD5HashToBuffer(char* buff, int len)
+int MethodContext::dumpMethodMD5HashToBuffer(char* buff, int len, bool ignoreMethodName /* = false */)
 {
     char bufferIdentityInfo[METHOD_IDENTITY_INFO_SIZE];
 
-    int cbLen = dumpMethodIdentityInfoToBuffer(bufferIdentityInfo, METHOD_IDENTITY_INFO_SIZE);
+    int cbLen = dumpMethodIdentityInfoToBuffer(bufferIdentityInfo, METHOD_IDENTITY_INFO_SIZE, ignoreMethodName);
 
     if (cbLen < 0)
         return cbLen;

src/coreclr/src/ToolBox/superpmi/superpmi-shared/methodcontext.h

@@ -584,8 +584,8 @@ class MethodContext
     static int dumpStatTitleToBuffer(char* buff, int len);
     int methodSize;
 
-    int dumpMethodIdentityInfoToBuffer(char* buff, int len);
-    int dumpMethodMD5HashToBuffer(char* buff, int len);
+    int dumpMethodIdentityInfoToBuffer(char* buff, int len, bool ignoreMethodName = false);
+    int dumpMethodMD5HashToBuffer(char* buff, int len, bool ignoreMethodName = false);
 
     void recGlobalContext(const MethodContext& other);