[CHERI][ELF] Add missing REQUIRES to tests

Author: arichardson

lld/test/ELF/cheri/caprelocs-surrounding-symbol.s

@@ -1,5 +1,6 @@
 ## Check that lld uses the size of surrounding symbols for capability relocations
 ## against STT_NONE targets with size==0.
+# REQUIRES: riscv
 # RUN: %riscv64_cheri_purecap_llvm-mc -filetype=obj %s -o %t.o
 # RUN: llvm-readobj --symbols --relocations --cap-relocs --expand-relocs %t.o | FileCheck %s --check-prefix=OBJ-RELOCS
 # RUN: ld.lld -pie %t.o -o %t.exe -e fn1 --verbose 2>&1 | FileCheck %s --check-prefix=LLD-OUTPUT "--implicit-check-not=warning:"

lld/test/ELF/cheri/exception-table.ll

@@ -1,3 +1,4 @@
+; REQUIRES: riscv
 ; RUN: split-file %s %t
 ; RUN: %cheri_purecap_llc --relocation-model=pic < %t/input.ll -filetype=obj -o %t/mips.o
 ; RUN: %cheri_purecap_llc --relocation-model=pic < %t/weak_override.ll -filetype=obj -o %t/mips-override.o

lld/test/ELF/cheri/mips-libcxxrt-crash-cfi.s

@@ -1,5 +1,6 @@
 ## This used to crash ld.lld for CHERI MIPS with "internal linker error: wrote incorrect addend value 0x1043000000000 instead of 0x10430"
 ## The crash no longer occurs after b2559f2f5ca950e917253b156bfd08ede5577cd5
+# REQUIRES: mips
 # RUN: llvm-mc -filetype=obj -triple=mips64-unknown-freebsd --position-independent %s -o %t.o
 # RUN: ld.lld --eh-frame-hdr --shared -z notext -o %t.so %t.o
 # RUN: llvm-mc -filetype=obj -triple=mips64-unknown-freebsd %s -o %t-nopic.o