[MCParser] Remove some section directive not supported by gas

and not emitted by AsmPrinter.

The intention was to remove `.eh_frame`, which had the wrong
section flags. Let's also remove .data.rel and .data.rel.ro
but keep other extensions like .rodata

Author: MaskRay

llvm/lib/MC/MCParser/ELFAsmParser.cpp

@@ -57,12 +57,6 @@ class ELFAsmParser : public MCAsmParserExtension {
     addDirectiveHandler<&ELFAsmParser::parseSectionDirectiveRoData>(".rodata");
     addDirectiveHandler<&ELFAsmParser::parseSectionDirectiveTData>(".tdata");
     addDirectiveHandler<&ELFAsmParser::parseSectionDirectiveTBSS>(".tbss");
-    addDirectiveHandler<
-      &ELFAsmParser::parseSectionDirectiveDataRel>(".data.rel");
-    addDirectiveHandler<
-      &ELFAsmParser::parseSectionDirectiveDataRelRo>(".data.rel.ro");
-    addDirectiveHandler<
-      &ELFAsmParser::parseSectionDirectiveEhFrame>(".eh_frame");
     addDirectiveHandler<&ELFAsmParser::parseDirectiveSection>(".section");
     addDirectiveHandler<
       &ELFAsmParser::parseDirectivePushSection>(".pushsection");
@@ -120,22 +114,6 @@ class ELFAsmParser : public MCAsmParserExtension {
                               ELF::SHF_TLS | ELF::SHF_WRITE,
                               SectionKind::getThreadBSS());
   }
-  bool parseSectionDirectiveDataRel(StringRef, SMLoc) {
-    return parseSectionSwitch(".data.rel", ELF::SHT_PROGBITS,
-                              ELF::SHF_ALLOC | ELF::SHF_WRITE,
-                              SectionKind::getData());
-  }
-  bool parseSectionDirectiveDataRelRo(StringRef, SMLoc) {
-    return parseSectionSwitch(".data.rel.ro", ELF::SHT_PROGBITS,
-                              ELF::SHF_ALLOC |
-                              ELF::SHF_WRITE,
-                              SectionKind::getReadOnlyWithRel());
-  }
-  bool parseSectionDirectiveEhFrame(StringRef, SMLoc) {
-    return parseSectionSwitch(".eh_frame", ELF::SHT_PROGBITS,
-                              ELF::SHF_ALLOC | ELF::SHF_WRITE,
-                              SectionKind::getData());
-  }
   bool parseDirectivePushSection(StringRef, SMLoc);
   bool parseDirectivePopSection(StringRef, SMLoc);
   bool parseDirectiveSection(StringRef, SMLoc);

llvm/test/MC/ELF/elf_directive_section.s

@@ -3,15 +3,6 @@
 	.bss
 # CHECK: .bss
 
-	.data.rel.ro
-# CHECK: .data.rel.ro
-
-	.data.rel
-# CHECK: .data.rel
-
-	.eh_frame
-# CHECK: .eh_frame
-
 	.rodata
 # CHECK: .rodata