[SystemZ] Fix variable names to reflect Coding Standards (#161899)

Reflecting the [Coding
Standards](https://llvm.org/docs/CodingStandards.html), the following
changes were made to reflect this guideline.
```
Variable names should be nouns (as they represent state). The name should be camel case, and start with an upper-case letter (e.g. Leader or Boats).
```
The first letter in the variable names are changed to upper-case and
reflect being camel case.

Author: dvldogg

llvm/lib/Target/SystemZ/MCTargetDesc/SystemZInstPrinterCommon.cpp

@@ -184,8 +184,8 @@ void SystemZInstPrinterCommon::printPCRelTLSOperand(const MCInst *MI,
   // Output the TLS marker if present.
   if ((unsigned)OpNum + 1 < MI->getNumOperands()) {
     const MCOperand &MO = MI->getOperand(OpNum + 1);
-    const MCSymbolRefExpr &refExp = cast<MCSymbolRefExpr>(*MO.getExpr());
-    switch (refExp.getSpecifier()) {
+    const MCSymbolRefExpr &RefExp = cast<MCSymbolRefExpr>(*MO.getExpr());
+    switch (RefExp.getSpecifier()) {
     case SystemZ::S_TLSGD:
       O << ":tls_gdcall:";
       break;
@@ -195,7 +195,7 @@ void SystemZInstPrinterCommon::printPCRelTLSOperand(const MCInst *MI,
     default:
       llvm_unreachable("Unexpected symbol kind");
     }
-    O << refExp.getSymbol().getName();
+    O << RefExp.getSymbol().getName();
   }
 }
 

llvm/lib/Target/SystemZ/SystemZConstantPoolValue.cpp

@@ -13,10 +13,9 @@
 
 using namespace llvm;
 
-SystemZConstantPoolValue::
-SystemZConstantPoolValue(const GlobalValue *gv,
-                         SystemZCP::SystemZCPModifier modifier)
-  : MachineConstantPoolValue(gv->getType()), GV(gv), Modifier(modifier) {}
+SystemZConstantPoolValue::SystemZConstantPoolValue(
+    const GlobalValue *GV, SystemZCP::SystemZCPModifier Modifier)
+    : MachineConstantPoolValue(GV->getType()), GV(GV), Modifier(Modifier) {}
 
 SystemZConstantPoolValue *
 SystemZConstantPoolValue::Create(const GlobalValue *GV,

llvm/lib/Target/SystemZ/SystemZHazardRecognizer.cpp

@@ -352,10 +352,9 @@ int SystemZHazardRecognizer::groupingCost(SUnit *SU) const {
   // Similarly, a group-ending SU may either fit well (last in group), or
   // end the group prematurely.
   if (SC->EndGroup) {
-    unsigned resultingGroupSize =
-      (CurrGroupSize + getNumDecoderSlots(SU));
-    if (resultingGroupSize < 3)
-      return (3 - resultingGroupSize);
+    unsigned ResultingGroupSize = (CurrGroupSize + getNumDecoderSlots(SU));
+    if (ResultingGroupSize < 3)
+      return (3 - ResultingGroupSize);
     return -1;
   }