Add two i386 ELFs for CLE's linked-image ELF handling

tests_src/elf/hash_without_dynstr/build.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+# Rebuild the dangling-sh_link ELF fixture.
+#
+# Freestanding: no libc, no start files, so this needs only clang and GNU ld.
+# The linker script discards .dynstr while keeping .hash and .dynsym, so the
+# linker leaves sh_link = 0 in both -- the same section table u-boot images
+# carry. --emit-relocs keeps the link-time .rel sections around as u-boot does.
+# The build is deterministic; rebuilding produces the same bytes.
+set -euo pipefail
+cd "$(dirname "$0")"
+out=../../../tests/i386/hash_without_dynstr
+clang --target=i386-unknown-linux-gnu -c -fPIC -O1 -ffreestanding \
+    -fno-asynchronous-unwind-tables -o table.o table.c
+ld -m elf_i386 -pie --emit-relocs -T table.lds -o "$out" table.o
+rm -f table.o

tests_src/elf/hash_without_dynstr/table.c

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+/* A freestanding image whose only path to two of its functions is a table of
+   function pointers, the way u-boot's linker lists work. Built with a linker
+   script that discards .dynstr, which leaves .hash and .dynsym with an sh_link
+   that points at nothing -- the shape that used to make CLE throw the whole
+   section header table away, .symtab included. */
+static int counter;
+
+int table_helper(int x) { return x * 3 + counter; }
+int table_entry_one(void) { return table_helper(1); }
+int table_entry_two(void) { return table_helper(2); }
+
+int (*const entries[])(void) = {table_entry_one, table_entry_two};
+
+void _start(void) { counter = entries[0]() + entries[1](); }

tests_src/elf/hash_without_dynstr/table.lds

@@ -0,0 +1,21 @@
+/* Keeps .hash and .dynsym while discarding .dynstr, as u-boot's own linker
+   scripts do. The linker then writes sh_link = 0 into both of them. */
+ENTRY(_start)
+SECTIONS
+{
+	. = 0x1000;
+	.text : { *(.text*) }
+	.rodata : { *(.rodata*) }
+	.data : { *(.data*) }
+	.bss : { *(.bss*) *(COMMON) }
+	.hash : { *(.hash) }
+	.dynsym : { *(.dynsym) }
+	.rela.dyn : { *(.rela*) }
+	/DISCARD/ : { *(.dynstr*) }
+	/DISCARD/ : { *(.dynamic*) }
+	/DISCARD/ : { *(.interp*) }
+	/DISCARD/ : { *(.gnu*) }
+	/DISCARD/ : { *(.note*) }
+	/DISCARD/ : { *(.comment) }
+	/DISCARD/ : { *(.eh_frame*) }
+}

tests_src/elf/linked_with_emit_relocs/build.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+# Rebuild the already-linked-image relocation fixture.
+#
+# Freestanding: no libc, no start files, so this needs only clang and GNU ld.
+# The section table is ordinary; what the fixture carries is a fixed link
+# address of 0x1000 and, through --emit-relocs, the link-time .rel.text and
+# .rel.data the linker has already applied. The build is deterministic;
+# rebuilding produces the same bytes.
+set -euo pipefail
+cd "$(dirname "$0")"
+out=../../../tests/i386/linked_with_emit_relocs
+clang --target=i386-unknown-linux-gnu -c -fPIC -O1 -ffreestanding \
+    -fno-asynchronous-unwind-tables -o table.o table.c
+ld -m elf_i386 -pie --emit-relocs -T table.lds -o "$out" table.o
+rm -f table.o

tests_src/elf/linked_with_emit_relocs/table.c

@@ -0,0 +1,14 @@
+/* A freestanding image whose only path to two of its functions is a table of
+   function pointers, the way u-boot's linker lists work. Built with a linker
+   script that discards .dynstr, which leaves .hash and .dynsym with an sh_link
+   that points at nothing -- the shape that used to make CLE throw the whole
+   section header table away, .symtab included. */
+static int counter;
+
+int table_helper(int x) { return x * 3 + counter; }
+int table_entry_one(void) { return table_helper(1); }
+int table_entry_two(void) { return table_helper(2); }
+
+int (*const entries[])(void) = {table_entry_one, table_entry_two};
+
+void _start(void) { counter = entries[0]() + entries[1](); }

tests_src/elf/linked_with_emit_relocs/table.lds

@@ -0,0 +1,23 @@
+/* An ordinary linker script for a fixed-address image: nothing unusual in the
+   section table, so every ELF reader parses it. What matters is that the image
+   is linked at 0x1000 rather than at 0, and that --emit-relocs leaves the
+   link-time .rel sections behind the way u-boot's build does. */
+ENTRY(_start)
+SECTIONS
+{
+	. = 0x1000;
+	.text : { *(.text*) }
+	.rodata : { *(.rodata*) }
+	.data : { *(.data*) }
+	.bss : { *(.bss*) *(COMMON) }
+	.rel.dyn : { *(.rel.dyn) }
+	/DISCARD/ : { *(.hash) }
+	/DISCARD/ : { *(.dynsym) }
+	/DISCARD/ : { *(.dynstr*) }
+	/DISCARD/ : { *(.dynamic*) }
+	/DISCARD/ : { *(.interp*) }
+	/DISCARD/ : { *(.gnu*) }
+	/DISCARD/ : { *(.note*) }
+	/DISCARD/ : { *(.comment) }
+	/DISCARD/ : { *(.eh_frame*) }
+}