[dwarfdump] Pretty print location expressions and location lists

Summary:
Based on Fred's patch here: https://reviews.llvm.org/D6771

I can't seem to commandeer the old review, so I'm creating a new one.

With that change the locations exrpessions are pretty printed inline in the
DIE tree. The output looks like this for debug_loc entries:

    DW_AT_location [DW_FORM_data4]        (0x00000000
       0x0000000000000001 - 0x000000000000000b: DW_OP_consts +3
       0x000000000000000b - 0x0000000000000012: DW_OP_consts +7
       0x0000000000000012 - 0x000000000000001b: DW_OP_reg0 RAX, DW_OP_piece 0x4
       0x000000000000001b - 0x0000000000000024: DW_OP_breg5 RDI+0)

And like this for debug_loc.dwo entries:
    DW_AT_location [DW_FORM_sec_offset]   (0x00000000
      Addr idx 2 (w/ length 190): DW_OP_consts +0, DW_OP_stack_value
      Addr idx 3 (w/ length 23): DW_OP_reg0 RAX, DW_OP_piece 0x4)

Simple locations without ranges are printed inline:

   DW_AT_location [DW_FORM_block1]       (DW_OP_reg4 RSI, DW_OP_piece 0x4, DW_OP_bit_piece 0x20 0x0)

The debug_loc(.dwo) dumping in changed accordingly to factor the code.

Reviewers: dblaikie, aprantl, friss

Subscribers: mgorny, javed.absar, hiraditya, llvm-commits, JDevlieghere

Differential Revision: https://reviews.llvm.org/D37123

llvm-svn: 312042
diff --git a/llvm/test/DebugInfo/X86/array.ll b/llvm/test/DebugInfo/X86/array.ll
index ed13b97..eba0bb4 100644
--- a/llvm/test/DebugInfo/X86/array.ll
+++ b/llvm/test/DebugInfo/X86/array.ll
@@ -21,8 +21,7 @@
 ; CHECK: callq _f
 
 ; DWARF: DW_TAG_variable
-; 	"<0x2> 91 00" means fbreg 0, i.e. offset RSP+0.
-; DWARF-NEXT:              DW_AT_location [DW_FORM_exprloc]      (<0x2> 91 00 )
+; DWARF-NEXT:              DW_AT_location [DW_FORM_exprloc]      (DW_OP_fbreg +0)
 ; DWARF-NEXT:              DW_AT_name [DW_FORM_strp]     ( {{.*}} = "array")
 
 ; ModuleID = '/tmp/array.c'