[lld] Add REQUIRES: x86 where needed to tests

If building lld without x86 support, tests that require that support should
be treated as unsupported, not errors.

Tested using:
  1. cmake '-DLLVM_TARGETS_TO_BUILD=AArch64;X86'
     make check-lld
     =>
     Expected Passes    : 1406
     Unsupported Tests  : 287

  2. cmake '-DLLVM_TARGETS_TO_BUILD=AArch64'
     make check-lld
     =>
     Expected Passes    : 410
     Unsupported Tests  : 1283

Patch by Joel Jones

Differential Revision: https://reviews.llvm.org/D47748

llvm-svn: 334095
diff --git a/lld/test/COFF/icf-pdata.s b/lld/test/COFF/icf-pdata.s
index ebd8479..8f5b3bae 100644
--- a/lld/test/COFF/icf-pdata.s
+++ b/lld/test/COFF/icf-pdata.s
@@ -1,3 +1,4 @@
+# REQUIRES: x86
 # RUN: llvm-mc %s -triple x86_64-windows-msvc -filetype=obj -o %t.obj
 # RUN: lld-link %t.obj -dll -noentry -out:%t.dll -merge:.xdata=.xdata
 # RUN: llvm-readobj -sections -coff-exports %t.dll | FileCheck %s