fix Issue 1528 - [tdpl] overloading template and non-template functions

- Improve `resolveFuncCall` for integrated function call resolution.
  All of error reporting is done in here.

- Remove `overloadResolve` and `deduceFuncitonTemplate`
  The works was in `overloadResolve` are moved to `resolveFuncCall`,
  and things was in `deduceFuncitonTemplate` are divided to
  `templateResolve` and `resolveFuncCall`.

- Change the name from `overloadResolveX` to `functionResolve`
  It is paired with `templateResolve`.

- Decide 'most specialized' function based on the two `MATCH` values derived from `tiargs` and `fargs`.
  With non template functions, `last matching level for tiargs` is treated as `MATCHexact`.

----
The bug that is fixed at the same time:
fix Issue 9596 - Ambiguous match is incorrectly hidden by additional lesser match

  The change in test/runnable/template9.d is related.

src/declaration.h

@@ -102,8 +102,10 @@ struct Match
     FuncDeclaration *anyf;      // pick a func, any func, to use for error recovery
 };
 
-void overloadResolveX(Match *m, FuncDeclaration *f,
+void functionResolve(Match *m, FuncDeclaration *f,
         Type *tthis, Expressions *arguments, Dsymbol **plast = NULL);
+void templateResolve(Match *m, TemplateDeclaration *td, Loc loc, Scope *sc,
+        Objects *tiargs, Type *tthis, Expressions *fargs);
 int overloadApply(FuncDeclaration *fstart,
         int (*fp)(void *, FuncDeclaration *),
         void *param, Dsymbol **plast = NULL);
@@ -669,7 +671,6 @@ class FuncDeclaration : public Declaration
     int findVtblIndex(Dsymbols *vtbl, int dim);
     bool overloadInsert(Dsymbol *s);
     FuncDeclaration *overloadExactMatch(Type *t);
-    FuncDeclaration *overloadResolve(Loc loc, Type *tthis, Expressions *arguments, int flags = 0);
     TemplateDeclaration *findTemplateDeclRoot();
     MATCH leastAsSpecialized(FuncDeclaration *g);
     LabelDsymbol *searchLabel(Identifier *ident);

src/expression.c

@@ -1747,12 +1747,12 @@ void argsToCBuffer(OutBuffer *buf, Expressions *expressions, HdrGenState *hgs)
 
 void argExpTypesToCBuffer(OutBuffer *buf, Expressions *arguments, HdrGenState *hgs)
 {
-    if (arguments)
-    {   OutBuffer argbuf;
-
+    if (arguments && arguments->dim)
+    {
+        OutBuffer argbuf;
         for (size_t i = 0; i < arguments->dim; i++)
-        {   Expression *e = (*arguments)[i];
-
+        {
+            Expression *e = (*arguments)[i];
             if (i)
                 buf->writestring(", ");
             argbuf.reset();