Fix linker tests

These tests were expecting the old `bc 0, 0` / `bcr 0, %r0`
disassemblies for nops. This commit changes them to expect
the proper mnemonics in disassembly.

Author: dominik-steenken

lld/test/ELF/systemz-gotent-relax-und-dso.s

@@ -14,9 +14,9 @@
 # DISASM:      Disassembly of section .text:
 # DISASM-EMPTY:
 # DISASM-NEXT: <foo>:
-# DISASM-NEXT:     bc 0, 0
+# DISASM-NEXT:     nop     0
 # DISASM:      <hid>:
-# DISASM-NEXT:     bc 0, 0
+# DISASM-NEXT:     nop     0
 # DISASM:      <_start>:
 # DISASM-NEXT:    lgrl    %r1, 0x2400
 # DISASM-NEXT:    lgrl    %r1, 0x2400

lld/test/ELF/systemz-gotent-relax.s

@@ -30,9 +30,9 @@
 
 # DISASM:      Disassembly of section .text:
 # DISASM: 00000000010011e0 <foo>:
-# DISASM-NEXT:   bc      0, 0
+# DISASM-NEXT:   nop 0
 # DISASM: 00000000010011e4 <hid>:
-# DISASM-NEXT:   bc      0, 0
+# DISASM-NEXT:   nop 0
 # DISASM: 00000000010011e8 <ifunc>:
 # DISASM-NEXT:   br      %r14
 # DISASM: 00000000010011ea <_start>:

lld/test/ELF/systemz-init-padding.s

@@ -12,7 +12,7 @@
 
 # CHECK:      <.init>:
 # CHECK-NEXT: brasl %r14,
-# CHECK-NEXT: bcr     0, %r7
+# CHECK-NEXT: nopr   %r7
 # CHECK-NEXT: lg %r4, 272(%r15)
 
 	.text

lld/test/ELF/systemz-plt.s

@@ -48,9 +48,9 @@
 # DIS-NEXT: 100102c: d2 07 f0 30 10 08    	mvc	48(8,%r15), 8(%r1)
 # DIS-NEXT: 1001032: e3 10 10 10 00 04    	lg	%r1, 16(%r1)
 # DIS-NEXT: 1001038: 07 f1        	br	%r1
-# DIS-NEXT: 100103a: 07 00        	bcr	0, %r0
-# DIS-NEXT: 100103c: 07 00        	bcr	0, %r0
-# DIS-NEXT: 100103e: 07 00        	bcr	0, %r0
+# DIS-NEXT: 100103a: 07 00        	nopr   %r0
+# DIS-NEXT: 100103c: 07 00        	nopr   %r0
+# DIS-NEXT: 100103e: 07 00        	nopr   %r0
 # DIS-NEXT: 1001040: c0 10 00 00 10 54    	larl	%r1, 0x10030e8
 # DIS-NEXT: 1001046: e3 10 10 00 00 04    	lg	%r1, 0(%r1)
 # DIS-NEXT: 100104c: 07 f1        	br	%r1