Updating template files in the Text Assembler script

This patch contains minor changes in jinja template files.
These changes are made to align generated header files to work
with the last upstreamed version of Text Assembler.
diff --git a/tools/tasm_generator/tasm-template/tasm-assembler.jinja2 b/tools/tasm_generator/tasm-template/tasm-assembler.jinja2
index 889ba85..c6cffd4 100644
--- a/tools/tasm_generator/tasm-template/tasm-assembler.jinja2
+++ b/tools/tasm_generator/tasm-template/tasm-assembler.jinja2
@@ -58,13 +58,9 @@
 
 class TextAssembler : private Assembler {
  public:
-  TextAssembler() = default;
-  explicit TextAssembler(std::string filename) : eh_{filename} {};
   void Assemble(std::string instruction);
   bool GetError();
   bool GetLineError();
-  std::string GetLine();
-  std::string GetPrototype();
 
   // Functions allowing instruction prototype/mnemonic lookup.
   static bool MnemonicExists(std::string prototype, std::string mnemonic);
@@ -78,8 +74,6 @@
   vixl::internal::AssemblerBase *AsAssemblerBase();
 
  private:
-  std::string line;
-  std::string curr_prototype;
   ErrorHandler eh_;
   InstructionParser ip_ {MnemonicExists, GetPrototypes, &eh_};
   static const std::vector<std::string> str_prototypes_;
@@ -91,6 +85,31 @@
   {% endfor -%}
   static const std::map<std::string, std::map<std::string, AssemblerFn> >
       prototypes_;
+
+  // Functions below are wrappers around Assembler methods, they are generated
+  // in two cases.
+  //
+  // 1) For Assembler methods with default arguments. For example:
+  //     - cntd(const Register& rd, int pattern = SVE_ALL, int multiplier = 1)
+  //
+  //    For the above function two other ones will be generated:
+  //     - cntd(const Register& rd)
+  //     - cntd(const Register& rd, int pattern)
+  //
+  //    Text Assembler holds pointers to functions and needs explicit
+  //    signatures to refer to this functions omitting default arguments.
+  //
+  // 2) For Assembler methods that take base type argument governing few
+  //    subtypes. For example:
+  //   -movprfx(const ZRegister& zd, const PRegister& pg, const ZRegister& zn)
+  //
+  //    For the above function two other ones will be generated:
+  //   -movprfx(const ZRegister& zd, const PRegisterM& pg, const ZRegister& zn)
+  //   -movprfx(const ZRegister& zd, const PRegisterZ& pg, const ZRegister& zn)
+  //
+  //    PRegisterM and PRegisterZ are subtypes of the PRegister type.
+  //    Text Assembler parses arguments to the exact types and refers to the
+  //    function signatures with these types.
 {% for mnemonic, arguments in functions.items() %}
   using Assembler::{{ mnemonic.hdr_name }};
   {%- for signature, names in arguments %}