ANDROID: vmlinux.lds.h: merge compound literal sections

After LLVM rG9e33c096476a ("[ELF] Keep orphan section names
(.rodata.foo .text.foo) unchanged if !hasSectionsCommand"), LLD splits
compound literals to separate sections with -fdata-sections, which
it always enables with LTO. Merge these sections to allow LLVM to be
upgraded.

Bug: 174047799
Bug: 175351675
Change-Id: I858c5fcc48283d5528c1d3e2b2d7a3c72f9e03d6
Link: ClangBuiltLinux/linux#958
Suggested-by: Danny Lin <[email protected]>
Suggested-by: Fangrui Song <[email protected]>
Signed-off-by: Sami Tolvanen <[email protected]>
Signed-off-by: Nick Desaulniers <[email protected]>
Signed-off-by: atndko <[email protected]>

include/asm-generic/vmlinux.lds.h

@@ -65,11 +65,11 @@
  * .data. We don't want to pull in .data..other sections, which Linux
  * has defined. Same for text and bss.
  */
-#ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
+#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CLANG)
 #define TEXT_MAIN .text .text.[0-9a-zA-Z_]*
 #define TEXT_CFI_MAIN .text.cfi .text.[0-9a-zA-Z_]*.cfi
-#define DATA_MAIN .data .data.[0-9a-zA-Z_]*
-#define BSS_MAIN .bss .bss.[0-9a-zA-Z_]*
+#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliteral*
+#define BSS_MAIN .bss .bss.[0-9a-zA-Z_]* .bss..compoundliteral*
 #else
 #define TEXT_MAIN .text
 #define TEXT_CFI_MAIN .text.cfi