[CSKY] Create mapping symbols with non-unique names

Similar to #99836 for AArch64.

Non-unique names save .strtab space and match GNU assembler.

Author: MaskRay

llvm/lib/Target/CSKY/MCTargetDesc/CSKYELFStreamer.cpp

@@ -168,8 +168,7 @@ void CSKYELFStreamer::EmitMappingSymbol(StringRef Name) {
 
   State = (Name == "$t" ? EMS_Text : EMS_Data);
 
-  auto *Symbol = cast<MCSymbolELF>(getContext().getOrCreateSymbol(
-      Name + "." + Twine(MappingSymbolCounter++)));
+  auto *Symbol = cast<MCSymbolELF>(getContext().createLocalSymbol(Name));
   emitLabel(Symbol);
 
   Symbol->setType(ELF::STT_NOTYPE);

llvm/lib/Target/CSKY/MCTargetDesc/CSKYELFStreamer.h

@@ -99,8 +99,6 @@ class CSKYTargetELFStreamer : public CSKYTargetStreamer {
 };
 
 class CSKYELFStreamer : public MCELFStreamer {
-  int64_t MappingSymbolCounter = 0;
-
   void EmitMappingSymbol(StringRef Name);
 
 public:
@@ -138,7 +136,6 @@ class CSKYELFStreamer : public MCELFStreamer {
     MCELFStreamer::emitValueImpl(Value, Size, Loc);
   }
   void reset() override {
-    MappingSymbolCounter = 0;
     State = EMS_None;
     MCELFStreamer::reset();
   }

llvm/test/DebugInfo/Symbolize/ELF/csky-mapping-symbol.s

@@ -5,11 +5,11 @@
 
 ## Verify that mapping symbols are actually present in the object at expected
 ## addresses.
-# RUN: llvm-nm --special-syms %t | FileCheck %s -check-prefix MAPPING_SYM
+# RUN: llvm-nm --special-syms %t | FileCheck %s -check-prefix MAPPING_SYM --match-full-lines
 
-# MAPPING_SYM:      00000000 t $d.0
-# MAPPING_SYM-NEXT: 00000008 t $d.2
-# MAPPING_SYM-NEXT: 00000004 t $t.1
+# MAPPING_SYM:      00000000 t $d
+# MAPPING_SYM-NEXT: 00000008 t $d
+# MAPPING_SYM-NEXT: 00000004 t $t
 # MAPPING_SYM-NEXT: 00000000 T foo
 
 # RUN: llvm-symbolizer --obj=%t 0 4 0xc | FileCheck %s -check-prefix SYMBOL