Fix the interpretation of a 0 st_name.

The ELF spec is very clear:

-----------------------------------------------------------------------------
If the value is non-zero, it represents a string table index that gives the
symbol name. Otherwise, the symbol table entry has no name.
--------------------------------------------------------------------------

In particular, a st_name of 0 most certainly doesn't mean that the symbol has
the same name as the section.

llvm-svn: 238899
diff --git a/llvm/test/Object/obj2yaml.test b/llvm/test/Object/obj2yaml.test
index 2a3f7c8..08000f6 100644
--- a/llvm/test/Object/obj2yaml.test
+++ b/llvm/test/Object/obj2yaml.test
@@ -267,26 +267,19 @@
 ELF-MIPSEL-NEXT:       Type:            STT_OBJECT
 ELF-MIPSEL-NEXT:       Section:         .rodata.str1.1
 ELF-MIPSEL-NEXT:       Size:            0x000000000000000D
-ELF-MIPSEL-NEXT:     - Name:            .text
-ELF-MIPSEL-NEXT:       Type:            STT_SECTION
+ELF-MIPSEL-NEXT:     - Type:            STT_SECTION
 ELF-MIPSEL-NEXT:       Section:         .text
-ELF-MIPSEL-NEXT:     - Name:            .data
-ELF-MIPSEL-NEXT:       Type:            STT_SECTION
+ELF-MIPSEL-NEXT:     - Type:            STT_SECTION
 ELF-MIPSEL-NEXT:       Section:         .data
-ELF-MIPSEL-NEXT:     - Name:            .bss
-ELF-MIPSEL-NEXT:       Type:            STT_SECTION
+ELF-MIPSEL-NEXT:     - Type:            STT_SECTION
 ELF-MIPSEL-NEXT:       Section:         .bss
-ELF-MIPSEL-NEXT:     - Name:            .mdebug.abi32
-ELF-MIPSEL-NEXT:       Type:            STT_SECTION
+ELF-MIPSEL-NEXT:     - Type:            STT_SECTION
 ELF-MIPSEL-NEXT:       Section:         .mdebug.abi32
-ELF-MIPSEL-NEXT:     - Name:            .rodata.str1.1
-ELF-MIPSEL-NEXT:       Type:            STT_SECTION
+ELF-MIPSEL-NEXT:     - Type:            STT_SECTION
 ELF-MIPSEL-NEXT:       Section:         .rodata.str1.1
-ELF-MIPSEL-NEXT:     - Name:            .reginfo
-ELF-MIPSEL-NEXT:       Type:            STT_SECTION
+ELF-MIPSEL-NEXT:     - Type:            STT_SECTION
 ELF-MIPSEL-NEXT:       Section:         .reginfo
-ELF-MIPSEL-NEXT:     - Name:            .MIPS.abiflags
-ELF-MIPSEL-NEXT:       Type:            STT_SECTION
+ELF-MIPSEL-NEXT:     - Type:            STT_SECTION
 ELF-MIPSEL-NEXT:       Section:         .MIPS.abiflags
 ELF-MIPSEL-NEXT:   Global:
 ELF-MIPSEL-NEXT:     - Name:            main
@@ -343,22 +336,17 @@
 ELF-MIPS64EL-NEXT:     Content:         ''
 ELF-MIPS64EL-NEXT: Symbols:
 ELF-MIPS64EL-NEXT:   Local:
-ELF-MIPS64EL-NEXT:     - Name:            .text
-ELF-MIPS64EL-NEXT:       Type:            STT_SECTION
+ELF-MIPS64EL-NEXT:     - Type:            STT_SECTION
 ELF-MIPS64EL-NEXT:       Section:         .text
-ELF-MIPS64EL-NEXT:     - Name:            .data
-ELF-MIPS64EL-NEXT:       Type:            STT_SECTION
+ELF-MIPS64EL-NEXT:     - Type:            STT_SECTION
 ELF-MIPS64EL-NEXT:       Section:         .data
-ELF-MIPS64EL-NEXT:     - Name:            .bss
-ELF-MIPS64EL-NEXT:       Type:            STT_SECTION
+ELF-MIPS64EL-NEXT:     - Type:            STT_SECTION
 ELF-MIPS64EL-NEXT:       Section:         .bss
 ELF-MIPS64EL-NEXT:     - Name:            bar
 ELF-MIPS64EL-NEXT:       Section:         .data
-ELF-MIPS64EL-NEXT:     - Name:            .MIPS.options
-ELF-MIPS64EL-NEXT:       Type:            STT_SECTION
+ELF-MIPS64EL-NEXT:     - Type:            STT_SECTION
 ELF-MIPS64EL-NEXT:       Section:         .MIPS.options
-ELF-MIPS64EL-NEXT:     - Name:            .pdr
-ELF-MIPS64EL-NEXT:       Type:            STT_SECTION
+ELF-MIPS64EL-NEXT:     - Type:            STT_SECTION
 ELF-MIPS64EL-NEXT:       Section:         .pdr
 ELF-MIPS64EL-NEXT:   Global:
 ELF-MIPS64EL-NEXT:     - Name:            zed
@@ -394,7 +382,7 @@
 ELF-X86-64-NEXT:     Info:            .text
 ELF-X86-64-NEXT:     Relocations:
 ELF-X86-64-NEXT:       - Offset:          0x000000000000000D
-ELF-X86-64-NEXT:         Symbol:          .rodata.str1.1
+ELF-X86-64-NEXT:         Symbol:          ''
 ELF-X86-64-NEXT:         Type:            R_X86_64_32S
 ELF-X86-64-NEXT:       - Offset:          0x0000000000000012
 ELF-X86-64-NEXT:         Symbol:          puts
@@ -408,14 +396,11 @@
 ELF-X86-64-NEXT:   Local:
 ELF-X86-64-NEXT:     - Name:            trivial-object-test.s
 ELF-X86-64-NEXT:       Type:            STT_FILE
-ELF-X86-64-NEXT:     - Name:            .text
-ELF-X86-64-NEXT:       Type:            STT_SECTION
+ELF-X86-64-NEXT:     - Type:            STT_SECTION
 ELF-X86-64-NEXT:       Section:         .text
-ELF-X86-64-NEXT:     - Name:            .rodata.str1.1
-ELF-X86-64-NEXT:       Type:            STT_SECTION
+ELF-X86-64-NEXT:     - Type:            STT_SECTION
 ELF-X86-64-NEXT:       Section:         .rodata.str1.1
-ELF-X86-64-NEXT:     - Name:            .note.GNU-stack
-ELF-X86-64-NEXT:       Type:            STT_SECTION
+ELF-X86-64-NEXT:     - Type:            STT_SECTION
 ELF-X86-64-NEXT:       Section:         .note.GNU-stack
 ELF-X86-64-NEXT:   Global:
 ELF-X86-64-NEXT:     - Name:            main