LoongArch: extable: Also recognize ABI names of registers

When the kernel is compiled with LLVM, the register names being handled
during exception fixup building are ABI names instead of bare $rNN
style. Add mapping for the ABI names for LLVM compatibility.
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

arch/loongarch/include/asm/gpr-num.h

@@ -9,6 +9,22 @@
 	.equ	.L__gpr_num_$r\num, \num
 	.endr
 
+	/* ABI names of registers */
+	.equ	.L__gpr_num_$ra, 1
+	.equ	.L__gpr_num_$tp, 2
+	.equ	.L__gpr_num_$sp, 3
+	.irp	num,0,1,2,3,4,5,6,7
+	.equ	.L__gpr_num_$a\num, 4 + \num
+	.endr
+	.irp	num,0,1,2,3,4,5,6,7,8
+	.equ	.L__gpr_num_$t\num, 12 + \num
+	.endr
+	.equ	.L__gpr_num_$s9, 22
+	.equ	.L__gpr_num_$fp, 22
+	.irp	num,0,1,2,3,4,5,6,7,8
+	.equ	.L__gpr_num_$s\num, 23 + \num
+	.endr
+
 #else /* __ASSEMBLY__ */
 
 #define __DEFINE_ASM_GPR_NUMS					\
@@ -16,6 +32,20 @@
 "	.irp	num,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31\n" \
 "	.equ	.L__gpr_num_$r\\num, \\num\n"			\
 "	.endr\n"						\
+"	.equ	.L__gpr_num_$ra, 1\n"				\
+"	.equ	.L__gpr_num_$tp, 2\n"				\
+"	.equ	.L__gpr_num_$sp, 3\n"				\
+"	.irp	num,0,1,2,3,4,5,6,7\n"				\
+"	.equ	.L__gpr_num_$a\\num, 4 + \\num\n"		\
+"	.endr\n"						\
+"	.irp	num,0,1,2,3,4,5,6,7,8\n"			\
+"	.equ	.L__gpr_num_$t\\num, 12 + \\num\n"		\
+"	.endr\n"						\
+"	.equ	.L__gpr_num_$s9, 22\n"				\
+"	.equ	.L__gpr_num_$fp, 22\n"				\
+"	.irp	num,0,1,2,3,4,5,6,7,8\n"			\
+"	.equ	.L__gpr_num_$s\\num, 23 + \\num\n"		\
+"	.endr\n"						\
 
 #endif /* __ASSEMBLY__ */