vmlinux.lds.h: catch compound literals into data and BSS

When building kernel with LD_DEAD_CODE_DATA_ELIMINATION, LLVM stack
generates separate sections for compound literals, just like in case
with enabled LTO [0]:

ld.lld: warning: drivers/built-in.a(mtd/nand/spi/gigadevice.o):
(.data..compoundliteral.14) is being placed in
'.data..compoundliteral.14'
ld.lld: warning: drivers/built-in.a(mtd/nand/spi/gigadevice.o):
(.data..compoundliteral.15) is being placed in
'.data..compoundliteral.15'
ld.lld: warning: drivers/built-in.a(mtd/nand/spi/gigadevice.o):
(.data..compoundliteral.16) is being placed in
'.data..compoundliteral.16'
ld.lld: warning: drivers/built-in.a(mtd/nand/spi/gigadevice.o):
(.data..compoundliteral.17) is being placed in
'.data..compoundliteral.17'

[...]

Handle this by adding the related sections to generic definitions
as suggested by Sami [0].

[0] https://lore.kernel.org/lkml/20201211184633.3213045-3-samitolvanen@google.com

Suggested-by: Sami Tolvanen <samitolvanen@google.com>
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

include/asm-generic/vmlinux.lds.h

@@ -95,10 +95,10 @@
  */
 #ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
 #define TEXT_MAIN .text .text.[0-9a-zA-Z_]*
-#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..LPBX*
+#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliteral*
 #define SDATA_MAIN .sdata .sdata.[0-9a-zA-Z_]*
-#define RODATA_MAIN .rodata .rodata.[0-9a-zA-Z_]*
-#define BSS_MAIN .bss .bss.[0-9a-zA-Z_]*
+#define RODATA_MAIN .rodata .rodata.[0-9a-zA-Z_]* .rodata..L*
+#define BSS_MAIN .bss .bss.[0-9a-zA-Z_]* .bss..compoundliteral*
 #define SBSS_MAIN .sbss .sbss.[0-9a-zA-Z_]*
 #else
 #define TEXT_MAIN .text