Fix Issue 21222 - Add windows 64 bit version of rdmd

Author: RazvanN7

script/install.sh

@@ -1197,7 +1197,7 @@ write_env_vars() {
     echo "set _OLD_D_PATH=%PATH%"
     echo "set PATH=${DUB_BIN_PATH:+$(cygpath -w "${DUB_BIN_PATH}");}${winpath};%PATH%"
     if [[ $PROCESSOR_ARCHITECTURE != x86 ]]; then
-        echo "set PATH=${winpath}64;%PATH%"
+        echo "set PATH=${winpath}64;PATH%"
     fi
 } > "$ROOT/$1/activate.bat"
     fi

windows/d2-installer.nsi

@@ -295,6 +295,7 @@ SectionGroup /e "D2"
 
   Section "Add to PATH" AddD2ToPath
     ${EnvVarUpdate} $0 "PATH" "A" "HKLM" "$INSTDIR\dmd2\windows\bin"
+    ${EnvVarUpdate} $0 "PATH" "A" "HKLM" "$INSTDIR\dmd2\windows\bin64"
   SectionEnd