riscv64: consolidate riscv intrinsics into lib-riscv.c

Replace the single-purpose lib/riscvflush.c with lib/lib-riscv.c
following the lib-arm64.c naming convention.

lib/Makefile

@@ -73,7 +73,7 @@ OBJ-arm-vfp = $(OBJ-arm)
 OBJ-arm-eabi = $(OBJ-arm)
 OBJ-arm-eabihf = $(OBJ-arm)
 OBJ-arm-wince = $(ARM_O) $(WIN_O)
-OBJ-riscv64 = $(RISCV64_O) riscvflush.o $(LIN_O)
+OBJ-riscv64 = $(RISCV64_O) lib-riscv.o $(LIN_O)
 
 OBJ-extra = $(filter $(EXTRA_O),$(OBJ-$T))
 OBJ-libtcc1 = $(addprefix $(X),$(filter-out $(OBJ-extra),$(OBJ-$T)))

lib/lib-riscv.c

@@ -0,0 +1,20 @@
+/*
+ *  TCC runtime library for riscv64.
+ *
+ *  Copyright (c) 2026
+ *
+ * Copying and distribution of this file, with or without modification,
+ * are permitted in any medium without royalty provided the copyright
+ * notice and this notice are preserved.  This file is offered as-is,
+ * without any warranty.
+ */
+
+/* ------------------------------------------------------------- */
+/* __clear_cache is used in tccrun.c.  It is a built-in
+   intrinsic with gcc.  However tcc in order to compile
+   itself needs this function */
+
+void __clear_cache(void *beg, void *end)
+{
+    __riscv64_clear_cache(beg, end);
+}

lib/riscvflush.c

@@ -1,10 +0,0 @@
-/* riscvflush.c - flush the instruction cache
-
-   __clear_cache is used in tccrun.c,  It is a built-in
-   intrinsic with gcc.  However tcc in order to compile
-   itself needs this function */
-
-void __clear_cache(void *beg, void *end)
-{
-    __riscv64_clear_cache(beg, end);
-}