scripted-diff: rename DescriptorImpl m_script_arg to m_subdescriptor_arg

-BEGIN VERIFY SCRIPT-
sed -i -e 's/m_script_arg/m_subdescriptor_arg/g' src/script/descriptor.cpp
-END VERIFY SCRIPT-

Author: Sjors

src/script/descriptor.cpp

@@ -210,7 +210,7 @@ class DescriptorImpl : public Descriptor
     //! Public key arguments for this descriptor (size 1 for PK, PKH, WPKH; any size of Multisig).
     const std::vector<std::unique_ptr<PubkeyProvider>> m_pubkey_args;
     //! The sub-descriptor argument (nullptr for everything but SH and WSH).
-    const std::unique_ptr<DescriptorImpl> m_script_arg;
+    const std::unique_ptr<DescriptorImpl> m_subdescriptor_arg;
     //! The string name of the descriptor function.
     const std::string m_name;
 
@@ -221,23 +221,23 @@ class DescriptorImpl : public Descriptor
     /** A helper function to construct the scripts for this descriptor.
      *
      *  This function is invoked once for every CScript produced by evaluating
-     *  m_script_arg, or just once in case m_script_arg is nullptr.
+     *  m_subdescriptor_arg, or just once in case m_subdescriptor_arg is nullptr.
 
      *  @param pubkeys The evaluations of the m_pubkey_args field.
-     *  @param script The evaluation of m_script_arg (or nullptr when m_script_arg is nullptr).
+     *  @param script The evaluation of m_subdescriptor_arg (or nullptr when m_subdescriptor_arg is nullptr).
      *  @param out A FlatSigningProvider to put scripts or public keys in that are necessary to the solver.
      *             The script and pubkeys argument to this function are automatically added.
      *  @return A vector with scriptPubKeys for this descriptor.
      */
     virtual std::vector<CScript> MakeScripts(const std::vector<CPubKey>& pubkeys, const CScript* script, FlatSigningProvider& out) const = 0;
 
 public:
-    DescriptorImpl(std::vector<std::unique_ptr<PubkeyProvider>> pubkeys, std::unique_ptr<DescriptorImpl> script, const std::string& name) : m_pubkey_args(std::move(pubkeys)), m_script_arg(std::move(script)), m_name(name) {}
+    DescriptorImpl(std::vector<std::unique_ptr<PubkeyProvider>> pubkeys, std::unique_ptr<DescriptorImpl> script, const std::string& name) : m_pubkey_args(std::move(pubkeys)), m_subdescriptor_arg(std::move(script)), m_name(name) {}
 
     bool IsSolvable() const override
     {
-        if (m_script_arg) {
-            if (!m_script_arg->IsSolvable()) return false;
+        if (m_subdescriptor_arg) {
+            if (!m_subdescriptor_arg->IsSolvable()) return false;
         }
         return true;
     }
@@ -247,8 +247,8 @@ class DescriptorImpl : public Descriptor
         for (const auto& pubkey : m_pubkey_args) {
             if (pubkey->IsRange()) return true;
         }
-        if (m_script_arg) {
-            if (m_script_arg->IsRange()) return true;
+        if (m_subdescriptor_arg) {
+            if (m_subdescriptor_arg->IsRange()) return true;
         }
         return false;
     }
@@ -268,10 +268,10 @@ class DescriptorImpl : public Descriptor
             }
             ret += std::move(tmp);
         }
-        if (m_script_arg) {
+        if (m_subdescriptor_arg) {
             if (pos++) ret += ",";
             std::string tmp;
-            if (!m_script_arg->ToStringHelper(arg, tmp, priv)) return false;
+            if (!m_subdescriptor_arg->ToStringHelper(arg, tmp, priv)) return false;
             ret += std::move(tmp);
         }
         out = std::move(ret) + ")";
@@ -311,9 +311,9 @@ class DescriptorImpl : public Descriptor
             }
         }
         std::vector<CScript> subscripts;
-        if (m_script_arg) {
+        if (m_subdescriptor_arg) {
             FlatSigningProvider subprovider;
-            if (!m_script_arg->ExpandHelper(pos, arg, cache_read, subscripts, subprovider, cache_write)) return false;
+            if (!m_subdescriptor_arg->ExpandHelper(pos, arg, cache_read, subscripts, subprovider, cache_write)) return false;
             out = Merge(out, subprovider);
         }
 
@@ -324,7 +324,7 @@ class DescriptorImpl : public Descriptor
             out.origins.emplace(entry.first.GetID(), std::move(entry.second));
             out.pubkeys.emplace(entry.first.GetID(), entry.first);
         }
-        if (m_script_arg) {
+        if (m_subdescriptor_arg) {
             for (const auto& subscript : subscripts) {
                 out.scripts.emplace(CScriptID(subscript), subscript);
                 std::vector<CScript> addscripts = MakeScripts(pubkeys, &subscript, out);