[NFC] Remove leftover inline on some RuleMatcher functions

Accidentally copy-pasted them into the .cpp while refactoring the file in D151432
Those functions are currently only used in the .cpp so it didn't cause an issue, but it causes an undefined reference if another file attempts to use them.

llvm/utils/TableGen/GlobalISelMatchTable.cpp

@@ -792,7 +792,7 @@ void RuleMatcher::definePhysRegOperand(Record *Reg, OperandMatcher &OM) {
   }
 }
 
-inline InstructionMatcher &
+InstructionMatcher &
 RuleMatcher::getInstructionMatcher(StringRef SymbolicName) const {
   for (const auto &I : InsnVariableIDs)
     if (I.first->getSymbolicName() == SymbolicName)
@@ -801,8 +801,7 @@ RuleMatcher::getInstructionMatcher(StringRef SymbolicName) const {
       ("Failed to lookup instruction " + SymbolicName).str().c_str());
 }
 
-inline const OperandMatcher &
-RuleMatcher::getPhysRegOperandMatcher(Record *Reg) const {
+const OperandMatcher &RuleMatcher::getPhysRegOperandMatcher(Record *Reg) const {
   const auto &I = PhysRegOperands.find(Reg);
 
   if (I == PhysRegOperands.end()) {