[ELF] Make some diagnostics follow the convention

Author: MaskRay

lld/ELF/Arch/X86_64.cpp

@@ -947,7 +947,7 @@ void X86_64::relaxGot(uint8_t *loc, const Relocation &rel, uint64_t val) const {
 bool X86_64::adjustPrologueForCrossSplitStack(uint8_t *loc, uint8_t *end,
                                               uint8_t stOther) const {
   if (!config->is64) {
-    error("Target doesn't support split stacks.");
+    error("target doesn't support split stacks");
     return false;
   }
 

lld/ELF/InputSection.cpp

@@ -586,7 +586,7 @@ static Relocation *getRISCVPCRelHi20(const Symbol *sym, uint64_t addend) {
   InputSection *isec = cast<InputSection>(d->section);
 
   if (addend != 0)
-    warn("Non-zero addend in R_RISCV_PCREL_LO12 relocation to " +
+    warn("non-zero addend in R_RISCV_PCREL_LO12 relocation to " +
          isec->getObjMsg(d->value) + " is ignored");
 
   // Relocations are sorted by offset, so we can use std::equal_range to do
@@ -1136,7 +1136,7 @@ static void switchMorestackCallsToMorestackNonSplit(
   // __morestack_non_split.
   Symbol *moreStackNonSplit = symtab->find("__morestack_non_split");
   if (!moreStackNonSplit) {
-    error("Mixing split-stack objects requires a definition of "
+    error("mixing split-stack objects requires a definition of "
           "__morestack_non_split");
     return;
   }

lld/test/ELF/x86-64-split-stack-prologue-adjust-fail.s

@@ -12,7 +12,7 @@
 # RELOCATABLE: cannot mix split-stack and non-split-stack in a relocatable link
 
 # RUN: not ld.lld --defsym __morestack=0x100 --defsym _start=0x300 %t1.o %t2.o %t3.o -o /dev/null 2>&1 | FileCheck %s -check-prefix=ERROR
-# ERROR: Mixing split-stack objects requires a definition of __morestack_non_split
+# ERROR: mixing split-stack objects requires a definition of __morestack_non_split
 
 	.text