genksyms: Teach parser about 128-bit built-in types

__uint128_t crops up in a few files that export symbols to modules, so
teach genksyms about it and the other GCC built-in 128-bit integer types
so that we don't end up skipping the CRC generation for some symbols due
to the parser failing to spot them:

  | WARNING: EXPORT symbol "kernel_neon_begin" [vmlinux] version
  |          generation failed, symbol will not be versioned.
  | ld: arch/arm64/kernel/fpsimd.o: relocation R_AARCH64_ABS32 against
  |     `__crc_kernel_neon_begin' can not be used when making a shared
  |     object
  | ld: arch/arm64/kernel/fpsimd.o:(.data+0x0): dangerous relocation:
  |     unsupported relocation
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

scripts/genksyms/keywords.c

@@ -25,6 +25,10 @@ static struct resword {
 	{ "__volatile__", VOLATILE_KEYW },
 	{ "__builtin_va_list", VA_LIST_KEYW },
 
+	{ "__int128", BUILTIN_INT_KEYW },
+	{ "__int128_t", BUILTIN_INT_KEYW },
+	{ "__uint128_t", BUILTIN_INT_KEYW },
+
 	// According to rth, c99 defines "_Bool", __restrict", __restrict__", "restrict".  KAO
 	{ "_Bool", BOOL_KEYW },
 	{ "_restrict", RESTRICT_KEYW },

scripts/genksyms/parse.y

@@ -76,6 +76,7 @@ static void record_compound(struct string_list **keyw,
 %token ATTRIBUTE_KEYW
 %token AUTO_KEYW
 %token BOOL_KEYW
+%token BUILTIN_INT_KEYW
 %token CHAR_KEYW
 %token CONST_KEYW
 %token DOUBLE_KEYW
@@ -263,6 +264,7 @@ simple_type_specifier:
 	| VOID_KEYW
 	| BOOL_KEYW
 	| VA_LIST_KEYW
+	| BUILTIN_INT_KEYW
 	| TYPE			{ (*$1)->tag = SYM_TYPEDEF; $$ = $1; }
 	;