[lld][test][RISCV] Don't use incorrectly normalised arch string in riscv-attributes-place.s

Per the psABI, the arch string should be normalised to (amongest other
things) always include the full version of each extension in form
zfoo1p0. riscv-attributes-place.s didn't conform to this, which is not a
problem for the current parsing logic, but this behaviour would change
with a patch I'm about to propose.

This makes riscv-sttributes-place.s feature a valid arch string, and
maintains test coverage for this particular form of invalid arch string
by adding it to riscv-attributes.s.

Author: asb

lld/test/ELF/riscv-attributes-place.s

@@ -22,7 +22,7 @@
 .byte 1  # Tag_File
 .long .Lend-.Lbegin
 .byte 5  # Tag_RISCV_arch
-.asciz "rv64i2"
+.asciz "rv64i2p0"
 .Lend:
 
 .section .riscv.b,""

lld/test/ELF/riscv-attributes.s

@@ -26,6 +26,10 @@
 # RUN: not ld.lld unrecognized_version.o -o /dev/null 2>&1 | FileCheck %s --check-prefix=UNRECOGNIZED_VERSION --implicit-check-not=error:
 # UNRECOGNIZED_VERSION: error: unrecognized_version.o:(.riscv.attributes): rv64i99p0: unsupported version number 99.0 for extension 'i'
 
+# RUN: llvm-mc -filetype=obj -triple=riscv64 invalid_arch1.s -o invalid_arch1.o
+# RUN: ld.lld -e 0 invalid_arch1.o -o invalid_arch1
+# RUN: llvm-readobj --arch-specific invalid_arch1 | FileCheck %s --check-prefix=INVALID_ARCH1
+
 ## A zero value attribute is not printed.
 # RUN: llvm-mc -filetype=obj -triple=riscv64 unaligned_access_0.s -o unaligned_access_0.o
 # RUN: ld.lld -e 0 --fatal-warnings a.o unaligned_access_0.o -o unaligned_access_0
@@ -171,6 +175,34 @@
 .asciz "rv64i99p0"
 .Lend:
 
+#--- invalid_arch1.s
+# INVALID_ARCH1:      BuildAttributes {
+# INVALID_ARCH1-NEXT:   FormatVersion: 0x41
+# INVALID_ARCH1-NEXT:   Section 1 {
+# INVALID_ARCH1-NEXT:     SectionLength: 25
+# INVALID_ARCH1-NEXT:     Vendor: riscv
+# INVALID_ARCH1-NEXT:     Tag: Tag_File (0x1)
+# INVALID_ARCH1-NEXT:     Size: 15
+# INVALID_ARCH1-NEXT:     FileAttributes {
+# INVALID_ARCH1-NEXT:       Attribute {
+# INVALID_ARCH1-NEXT:         Tag: 5
+# INVALID_ARCH1-NEXT:         TagName: arch
+# INVALID_ARCH1-NEXT:         Value: rv64i2p0
+# INVALID_ARCH1-NEXT:       }
+# INVALID_ARCH1-NEXT:     }
+# INVALID_ARCH1-NEXT:   }
+# INVALID_ARCH1-NEXT: }
+.section .riscv.attributes,"",@0x70000003
+.byte 0x41
+.long .Lend-.riscv.attributes-1
+.asciz "riscv"  # vendor
+.Lbegin:
+.byte 1  # Tag_File
+.long .Lend-.Lbegin
+.byte 5  # Tag_RISCV_arch
+.asciz "rv64i2"
+.Lend:
+
 #--- unaligned_access_0.s
 .attribute unaligned_access, 0