riscv: Add tests for riscv module loading

Add test cases for the two main groups of relocations added: SUB and
SET, along with uleb128.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20231101-module_relocations-v9-3-8dfa3483c400@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/kernel/tests/module_test/test_uleb128.S

@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2023 Rivos Inc.
+ */
+
+.text
+.global test_uleb_basic
+test_uleb_basic:
+	ld	a0, second
+	addi	a0, a0, -127
+	ret
+
+.global test_uleb_large
+test_uleb_large:
+	ld	a0, fourth
+	addi	a0, a0, -0x07e8
+	ret
+
+.data
+first:
+	.space 127
+second:
+	.reloc second, R_RISCV_SET_ULEB128, second
+	.reloc second, R_RISCV_SUB_ULEB128, first
+	.dword 0
+third:
+	.space 1000
+fourth:
+	.reloc fourth, R_RISCV_SET_ULEB128, fourth
+	.reloc fourth, R_RISCV_SUB_ULEB128, third
+	.dword 0