[backport] fixes #23796; remove extra indirection for args in importc'ed functions in cpp (#23800)

fixes #23796

compiler/ccgcalls.nim

@@ -346,7 +346,8 @@ proc genArg(p: BProc, n: PNode, param: PSym; call: PNode; result: var Rope; need
     let callee = call[0]
     if callee.kind == nkSym and
         {sfImportc, sfInfixCall, sfCompilerProc} * callee.sym.flags == {sfImportc} and
-        {lfHeader, lfNoDecl} * callee.sym.loc.flags != {}:
+        {lfHeader, lfNoDecl} * callee.sym.loc.flags != {} and
+        needsIndirect:
       addAddrLoc(p.config, a, result)
     else:
       addRdLoc(a, result)

tests/ccgbugs/t23796.nim

@@ -0,0 +1,25 @@
+discard """
+    targets: "c cpp"
+"""
+
+# bug #23796
+
+{.emit: """
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void fooArr(float data[3]) {}
+void fooIntArr(int id, float data[3]) {}
+
+#ifdef __cplusplus
+}
+#endif
+""".}
+
+proc fooArr(data: var array[3, cfloat]) {.importc.}
+proc fooIntArr(id: cint, data: var array[3, cfloat]) {.importc, nodecl.}
+
+var arr = [cfloat 1, 2, 3]
+fooArr(arr)
+fooIntArr(1, arr)