[lld] Prefer printf over echo -e

Otherwise we break some MacOS bots when using the lit internal shell
because /bin/echo on MacOS does not support -e. Using the external shell
we end up using the echo builtin to /bin/bash, which does support this.

The echo builtin implementation in lit does support this, but that is
currently not enabled in pipelines. Might be worth looking into fixing
at some point.

Author: boomanaiden154

lld/test/COFF/reloc-discarded.s

@@ -1,5 +1,5 @@
 # REQUIRES: x86
-# RUN: echo -e '.section .bss,"bw",discard,main_global\n.global main_global\n main_global:\n .long 0' | \
+# RUN: printf '.section .bss,"bw",discard,main_global\n.global main_global\n main_global:\n .long 0' | \
 # RUN:     llvm-mc - -filetype=obj -o %t1.obj -triple x86_64-windows-msvc
 # RUN: llvm-mc %s -filetype=obj -o %t2.obj -triple x86_64-windows-msvc
 

lld/test/ELF/msp430.s

@@ -1,6 +1,6 @@
 ; REQUIRES: msp430
 ; RUN: llvm-mc -filetype=obj -triple=msp430-elf -o %t1.o %s
-; RUN: echo -e '.global _start\n _start: nop' | llvm-mc -filetype=obj -triple=msp430-elf -o %t2.o -
+; RUN: printf '.global _start\n _start: nop' | llvm-mc -filetype=obj -triple=msp430-elf -o %t2.o -
 ; RUN: ld.lld -o %t.exe --image-base=0x1000 --Tdata=0x2000 --Ttext=0x8000 --defsym=_byte=0x21 -z separate-code %t2.o %t1.o
 ; RUN: llvm-objdump -s -d %t.exe | FileCheck %s
 

lld/test/ELF/weak-shared-gc.s

@@ -1,6 +1,6 @@
 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t1.o
-# RUN: echo -e '.globl __cxa_finalize\n__cxa_finalize:' | \
+# RUN: printf '.globl __cxa_finalize\n__cxa_finalize:' | \
 # RUN:   llvm-mc -filetype=obj -triple=x86_64-pc-linux - -o %t2.o
 # RUN: ld.lld %t2.o -o %t2.so -shared
 # RUN: ld.lld %t1.o --as-needed --gc-sections %t2.so -o %t

lld/test/ELF/weak-undef-lib.s

@@ -1,6 +1,6 @@
 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t1.o
-# RUN: echo -e '.globl foo\nfoo: ret' | \
+# RUN: printf '.globl foo\nfoo: ret' | \
 # RUN:   llvm-mc -filetype=obj -triple=x86_64-pc-linux - -o %t2.o
 
 # RUN: ld.lld -shared -o %t.so %t1.o --start-lib %t2.o