[llvm-objdump][ARM] Not implement findPltEntries for ARM lead to parse plt entry incorrectly

[hstk30-hw]

#include <stdio.h>

void test() {
    printf("test\n");
    return;
}

with command: clang test.c -o -fPIC -shared test.so

the llvm-objdump output like:

Disassembly of section .plt:

00000310 <$a>:
     310: e52de004      str     lr, [sp, #-4]!
     314: e59fe004      ldr     lr, [pc, #4]            @ 0x320 <.plt+0x10>
     318: e08fe00e      add     lr, pc, lr
     31c: e5bef008      ldr     pc, [lr, #8]!

00000320 <$d>:
     320: e0 8c 00 00   .word   0x00008ce0

00000324 <$a>:
     324: e28fc600      add     r12, pc, #0, #12
     328: e28cca08      add     r12, r12, #8, #20
     32c: e5bcfce0      ldr     pc, [r12, #3296]!
     330: e28fc600      add     r12, pc, #0, #12
     334: e28cca08      add     r12, r12, #8, #20
     338: e5bcfcd8      ldr     pc, [r12, #3288]!
     33c: e28fc600      add     r12, pc, #0, #12
     340: e28cca08      add     r12, r12, #8, #20
     344: e5bcfcd0      ldr     pc, [r12, #3280]!
     348: e28fc600      add     r12, pc, #0, #12
     34c: e28cca08      add     r12, r12, #8, #20
     350: e5bcfcc8      ldr     pc, [r12, #3272]!
     354: e28fc600      add     r12, pc, #0, #12
     358: e28cca08      add     r12, r12, #8, #20
     35c: e5bcfcc0      ldr     pc, [r12, #3264]!

...

00000454 <test>:
     454: e92d4800      push    {r11, lr}
     458: e1a0b00d      mov     r11, sp
     45c: e59f0008      ldr     r0, [pc, #8]            @ 0x46c <test+0x18>
     460: e08f0000      add     r0, pc, r0
     464: ebffffb1      bl      0x330 <.plt+0x20>       @ imm = #-316
     468: e8bd8800      pop     {r11, pc}

llvm-project/llvm/lib/Object/ELFObjectFile.cpp

Lines 789 to 808 in 849e5ea

	switch (Triple.getArch()) {
	case Triple::x86:
	JumpSlotReloc = ELF::R_386_JUMP_SLOT;
	GlobDatReloc = ELF::R_386_GLOB_DAT;
	break;
	case Triple::x86_64:
	JumpSlotReloc = ELF::R_X86_64_JUMP_SLOT;
	GlobDatReloc = ELF::R_X86_64_GLOB_DAT;
	break;
	case Triple::aarch64:
	case Triple::aarch64_be:
	JumpSlotReloc = ELF::R_AARCH64_JUMP_SLOT;
	break;
	case Triple::hexagon:
	JumpSlotReloc = ELF::R_HEX_JMP_SLOT;
	GlobDatReloc = ELF::R_HEX_GLOB_DAT;
	break;
	default:
	return {};
	}

Not support for ARM32，

and we also need to implement findPltEntries for ARMMCInstrAnalysis class.

[llvmbot]

@llvm/issue-subscribers-backend-arm

Author: None (hstk30-hw)

``` #include <stdio.h>

void test() {
printf("test\n");
return;
}

with command: `clang test.c -o -fPIC -shared test.so`

the llvm-objdump output like:

Disassembly of section .plt:

00000310 <$a>:
310: e52de004 str lr, [sp, #-4]!
314: e59fe004 ldr lr, [pc, #4] @ 0x320 <.plt+0x10>
318: e08fe00e add lr, pc, lr
31c: e5bef008 ldr pc, [lr, #8]!

00000320 <$d>:
320: e0 8c 00 00 .word 0x00008ce0

00000324 <$a>:
324: e28fc600 add r12, pc, #0, #12
328: e28cca08 add r12, r12, #8, #20
32c: e5bcfce0 ldr pc, [r12, #3296]!
330: e28fc600 add r12, pc, #0, #12
334: e28cca08 add r12, r12, #8, #20
338: e5bcfcd8 ldr pc, [r12, #3288]!
33c: e28fc600 add r12, pc, #0, #12
340: e28cca08 add r12, r12, #8, #20
344: e5bcfcd0 ldr pc, [r12, #3280]!
348: e28fc600 add r12, pc, #0, #12
34c: e28cca08 add r12, r12, #8, #20
350: e5bcfcc8 ldr pc, [r12, #3272]!
354: e28fc600 add r12, pc, #0, #12
358: e28cca08 add r12, r12, #8, #20
35c: e5bcfcc0 ldr pc, [r12, #3264]!

...

00000454 <test>:
454: e92d4800 push {r11, lr}
458: e1a0b00d mov r11, sp
45c: e59f0008 ldr r0, [pc, #8] @ 0x46c <test+0x18>
460: e08f0000 add r0, pc, r0
464: ebffffb1 bl 0x330 <.plt+0x20> @ imm = #-316
468: e8bd8800 pop {r11, pc}

https://github.com/llvm/llvm-project/blob/849e5ea94fe8c0007f73ea793ba2a986608a67be/llvm/lib/Object/ELFObjectFile.cpp#L789-L808

Not support for ARM32，

and we also need to implement findPltEntries for ARMMCInstrAnalysis class.



</details>

[llvmbot]

@llvm/issue-subscribers-tools-llvm-objdump

Author: None (hstk30-hw)

``` #include <stdio.h>

void test() {
printf("test\n");
return;
}

with command: `clang test.c -o -fPIC -shared test.so`

the llvm-objdump output like:

Disassembly of section .plt:

00000310 <$a>:
310: e52de004 str lr, [sp, #-4]!
314: e59fe004 ldr lr, [pc, #4] @ 0x320 <.plt+0x10>
318: e08fe00e add lr, pc, lr
31c: e5bef008 ldr pc, [lr, #8]!

00000320 <$d>:
320: e0 8c 00 00 .word 0x00008ce0

00000324 <$a>:
324: e28fc600 add r12, pc, #0, #12
328: e28cca08 add r12, r12, #8, #20
32c: e5bcfce0 ldr pc, [r12, #3296]!
330: e28fc600 add r12, pc, #0, #12
334: e28cca08 add r12, r12, #8, #20
338: e5bcfcd8 ldr pc, [r12, #3288]!
33c: e28fc600 add r12, pc, #0, #12
340: e28cca08 add r12, r12, #8, #20
344: e5bcfcd0 ldr pc, [r12, #3280]!
348: e28fc600 add r12, pc, #0, #12
34c: e28cca08 add r12, r12, #8, #20
350: e5bcfcc8 ldr pc, [r12, #3272]!
354: e28fc600 add r12, pc, #0, #12
358: e28cca08 add r12, r12, #8, #20
35c: e5bcfcc0 ldr pc, [r12, #3264]!

...

00000454 <test>:
454: e92d4800 push {r11, lr}
458: e1a0b00d mov r11, sp
45c: e59f0008 ldr r0, [pc, #8] @ 0x46c <test+0x18>
460: e08f0000 add r0, pc, r0
464: ebffffb1 bl 0x330 <.plt+0x20> @ imm = #-316
468: e8bd8800 pop {r11, pc}

https://github.com/llvm/llvm-project/blob/849e5ea94fe8c0007f73ea793ba2a986608a67be/llvm/lib/Object/ELFObjectFile.cpp#L789-L808

Not support for ARM32，

and we also need to implement findPltEntries for ARMMCInstrAnalysis class.



</details>

[MaskRay]

Implemented by #130764