[ELF] Make tests with undefined symbols more explicit.

[ikudrin]

Summary

These changes are required for D38790, where undefined symbols are going to be removed from symbol tables if they are not really used.

[ruiu]

LGTM

lld/trunk/test/ELF/Inputs/shared3.s

 .global baz
-.type barz, @function
+.type baz, @function
 baz:

lld/trunk/test/ELF/gnu-hash-table.s

 # REQUIRES: x86,ppc
 
-# RUN: echo ".globl foo" > %te.s
+# RUN: echo ".globl foo; .data; .dc.a foo" > %te.s
 # RUN: llvm-mc -filetype=obj -triple=i386-pc-linux      %te.s -o %te-i386.o
 # RUN: llvm-mc -filetype=obj -triple=i386-pc-linux      %s    -o %t-i386.o
 # RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux    %s    -o %t-x86_64.o
 # RUN: llvm-mc -filetype=obj -triple=powerpc64-pc-linux %s    -o %t-ppc64.o
 
 # RUN: echo ".global zed; zed:" > %t2.s
 # RUN: llvm-mc -filetype=obj -triple=i386-pc-linux      %t2.s -o %t2-i386.o
 # RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux    %t2.s -o %t2-x86_64.o

 # PPC64-NEXT:   Values: [0xB8860BA, 0xB887389]
 # PPC64-NEXT: }
 
 .globl foo,bar,baz
 foo:
 bar:
 .weak zed
 .global xyz
+.data
+  .dc.a baz

lld/trunk/test/ELF/lto/shlib-undefined.ll

 ; REQUIRES: x86
 ; RUN: llvm-as %s -o %t.o
-; RUN: echo .global __progname > %t2.s
+; RUN: echo ".global __progname; .data; .dc.a __progname" > %t2.s
 ; RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %t2.s -o %t2.o
 ; RUN: ld.lld -shared %t2.o -o %t2.so
 ; RUN: ld.lld -o %t %t.o %t2.so
 ; RUN: llvm-readobj -dyn-symbols %t | FileCheck %s
 
 ; CHECK:      Name:     __progname@
 ; CHECK-NEXT: Value:    0x201010
 ; CHECK-NEXT: Size:     1

lld/trunk/test/ELF/progname.s

 // REQUIRES: x86
 // RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
-// RUN: echo .global __progname > %t2.s
+// RUN: echo ".global __progname; .data; .dc.a __progname" > %t2.s
 // RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %t2.s -o %t2.o
 // RUN: ld.lld -shared %t2.o -o %t2.so
 // RUN: ld.lld -o %t %t.o %t2.so
 // RUN: llvm-readobj -dyn-symbols %t | FileCheck %s
 
 // RUN: echo "VER_1 { global: bar; };" > %t.script
 // RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux \
 // RUN:   %p/Inputs/progname-ver.s -o %t-ver.o

lld/trunk/test/ELF/undef-version-script.s

 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
 # RUN: echo "{ local: *; };" > %t.script
 # RUN: ld.lld --version-script %t.script -shared %t.o -o %t.so
 # RUN: llvm-readobj -dyn-symbols %t.so | FileCheck %s
 
-# This does not match gold's behavior because gold does not create undefined
-# symbols in dynsym without an appropriate (e.g. PLT) relocation in the input.
-
 # CHECK:      DynamicSymbols [
 # CHECK-NEXT:   Symbol {
 # CHECK-NEXT:     Name: @
 # CHECK-NEXT:     Value: 0x0
 # CHECK-NEXT:     Size: 0
 # CHECK-NEXT:     Binding: Local (0x0)
 # CHECK-NEXT:     Type: None (0x0)
 # CHECK-NEXT:     Other: 0

 # CHECK-NEXT:     Type: None (0x0)
 # CHECK-NEXT:     Other: 0
 # CHECK-NEXT:     Section: Undefined (0x0)
 # CHECK-NEXT:   }
 # CHECK-NEXT: ]
 
 .global foo
 .weak bar
+.data
+  .dc.a foo
+  .dc.a bar

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

 # CHECK-NEXT:     Section: Undefined
 # CHECK-NEXT:   }
 # CHECK-NEXT: ]
 
 .weak foo
 
 .globl _start
 _start:
+
+.data
+  .dc.a foo