Make the tests more restrict

Author: Amirhossein Pashaeehir

llvm/test/DWARFCFIChecker/X86/empty-section.s

@@ -1,4 +1,6 @@
-# RUN: llvm-mc %s --validate-cfi --filetype=null 2>&1
+# RUN: llvm-mc %s --validate-cfi --filetype=null 2>&1 \
+# RUN:   | FileCheck %s --allow-empty 
+# CHECK-NOT: warning:
 .text
         .globl  f
         .type   f, @function

llvm/test/DWARFCFIChecker/X86/single-func.s

@@ -1,4 +1,5 @@
-# RUN: llvm-mc %s --validate-cfi --filetype=null
+# RUN: llvm-mc %s --validate-cfi --filetype=null 2>&1 \
+# RUN:   | FileCheck %s 
         .text
         .globl  f
         .type   f,@function

llvm/test/DWARFCFIChecker/X86/spill-two-reg.s

@@ -1,4 +1,5 @@
 # RUN: llvm-mc %s --validate-cfi --filetype=null
+# TODO: Should check no warnings are emitted but for now, the tool is naive and emiting warnings for evey change.
         .text
         .type   _start,@function
         .globl  _start
@@ -10,28 +11,34 @@ _start:
         .cfi_same_value %rsi
 
         pushq   %rbp
+        # CHECK: warning: unknown change happened to register RBP unwinding rule structure
         .cfi_adjust_cfa_offset 8
         .cfi_offset %rbp, -16
 
         movq    %rsp, %rbp
 
         pushq   %rdi
+        # CHECK: warning: unknown change happened to register RDI unwinding rule structure
         .cfi_adjust_cfa_offset 8
         .cfi_rel_offset %rdi, 0
 
         pushq   %rsi
+        # CHECK: warning: unknown change happened to register RSI unwinding rule structure
         .cfi_adjust_cfa_offset 8
         .cfi_rel_offset %rsi, 0
 
         popq    %rsi
+        # CHECK: warning: unknown change happened to register RSI unwinding rule structure
         .cfi_adjust_cfa_offset -8
         .cfi_same_value %rsi
 
         popq    %rdi
+        # CHECK: warning: unknown change happened to register RDI unwinding rule structure
         .cfi_adjust_cfa_offset -8
         .cfi_same_value %rdi
 
         popq    %rbp
+        # CHECK: warning: unknown change happened to register RBP unwinding rule structure
         .cfi_adjust_cfa_offset -8
         .cfi_same_value %rbp