[WebAssembly] clang-tidy (NFC)

Summary:
This patch fixes clang-tidy warnings on wasm-only files.
The list of checks used is:
`-*,clang-diagnostic-*,llvm-*,misc-*,-misc-unused-parameters,readability-identifier-naming,modernize-*`
(LLVM's default .clang-tidy list is the same except it does not have
`modernize-*`. But I've seen in multiple CLs in LLVM the modernize style
was recommended and code was fixed based on the style, so I added it as
well.)

The common fixes are:
- Variable names start with an uppercase letter
- Function names start with a lowercase letter
- Use `auto` when you use casts so the type is evident
- Use inline initialization for class member variables
- Use `= default` for empty constructors / destructors
- Use `using` in place of `typedef`

Reviewers: sbc100, tlively, aardappel

Subscribers: dschuff, sunfish, jgravelle-google, yurydelendik, kripken, MatzeB, mgorny, rupprecht, llvm-commits

Differential Revision: https://reviews.llvm.org/D57500

llvm-svn: 353075
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp
index f79fe04..dc8f3c3 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp
@@ -57,7 +57,7 @@
 }
 
 /// If desirable, rewrite NewReg to a drop register.
-static bool MaybeRewriteToDrop(unsigned OldReg, unsigned NewReg,
+static bool maybeRewriteToDrop(unsigned OldReg, unsigned NewReg,
                                MachineOperand &MO, WebAssemblyFunctionInfo &MFI,
                                MachineRegisterInfo &MRI) {
   bool Changed = false;
@@ -71,7 +71,7 @@
   return Changed;
 }
 
-static bool MaybeRewriteToFallthrough(MachineInstr &MI, MachineBasicBlock &MBB,
+static bool maybeRewriteToFallthrough(MachineInstr &MI, MachineBasicBlock &MBB,
                                       const MachineFunction &MF,
                                       WebAssemblyFunctionInfo &MFI,
                                       MachineRegisterInfo &MRI,
@@ -149,7 +149,7 @@
               if (MRI.getRegClass(NewReg) != MRI.getRegClass(OldReg))
                 report_fatal_error("Peephole: call to builtin function with "
                                    "wrong signature, from/to mismatch");
-              Changed |= MaybeRewriteToDrop(OldReg, NewReg, MO, MFI, MRI);
+              Changed |= maybeRewriteToDrop(OldReg, NewReg, MO, MFI, MRI);
             }
           }
         }
@@ -157,57 +157,57 @@
       }
       // Optimize away an explicit void return at the end of the function.
       case WebAssembly::RETURN_I32:
-        Changed |= MaybeRewriteToFallthrough(
+        Changed |= maybeRewriteToFallthrough(
             MI, MBB, MF, MFI, MRI, TII, WebAssembly::FALLTHROUGH_RETURN_I32,
             WebAssembly::COPY_I32);
         break;
       case WebAssembly::RETURN_I64:
-        Changed |= MaybeRewriteToFallthrough(
+        Changed |= maybeRewriteToFallthrough(
             MI, MBB, MF, MFI, MRI, TII, WebAssembly::FALLTHROUGH_RETURN_I64,
             WebAssembly::COPY_I64);
         break;
       case WebAssembly::RETURN_F32:
-        Changed |= MaybeRewriteToFallthrough(
+        Changed |= maybeRewriteToFallthrough(
             MI, MBB, MF, MFI, MRI, TII, WebAssembly::FALLTHROUGH_RETURN_F32,
             WebAssembly::COPY_F32);
         break;
       case WebAssembly::RETURN_F64:
-        Changed |= MaybeRewriteToFallthrough(
+        Changed |= maybeRewriteToFallthrough(
             MI, MBB, MF, MFI, MRI, TII, WebAssembly::FALLTHROUGH_RETURN_F64,
             WebAssembly::COPY_F64);
         break;
       case WebAssembly::RETURN_v16i8:
-        Changed |= MaybeRewriteToFallthrough(
+        Changed |= maybeRewriteToFallthrough(
             MI, MBB, MF, MFI, MRI, TII, WebAssembly::FALLTHROUGH_RETURN_v16i8,
             WebAssembly::COPY_V128);
         break;
       case WebAssembly::RETURN_v8i16:
-        Changed |= MaybeRewriteToFallthrough(
+        Changed |= maybeRewriteToFallthrough(
             MI, MBB, MF, MFI, MRI, TII, WebAssembly::FALLTHROUGH_RETURN_v8i16,
             WebAssembly::COPY_V128);
         break;
       case WebAssembly::RETURN_v4i32:
-        Changed |= MaybeRewriteToFallthrough(
+        Changed |= maybeRewriteToFallthrough(
             MI, MBB, MF, MFI, MRI, TII, WebAssembly::FALLTHROUGH_RETURN_v4i32,
             WebAssembly::COPY_V128);
         break;
       case WebAssembly::RETURN_v2i64:
-        Changed |= MaybeRewriteToFallthrough(
+        Changed |= maybeRewriteToFallthrough(
             MI, MBB, MF, MFI, MRI, TII, WebAssembly::FALLTHROUGH_RETURN_v2i64,
             WebAssembly::COPY_V128);
         break;
       case WebAssembly::RETURN_v4f32:
-        Changed |= MaybeRewriteToFallthrough(
+        Changed |= maybeRewriteToFallthrough(
             MI, MBB, MF, MFI, MRI, TII, WebAssembly::FALLTHROUGH_RETURN_v4f32,
             WebAssembly::COPY_V128);
         break;
       case WebAssembly::RETURN_v2f64:
-        Changed |= MaybeRewriteToFallthrough(
+        Changed |= maybeRewriteToFallthrough(
             MI, MBB, MF, MFI, MRI, TII, WebAssembly::FALLTHROUGH_RETURN_v2f64,
             WebAssembly::COPY_V128);
         break;
       case WebAssembly::RETURN_VOID:
-        Changed |= MaybeRewriteToFallthrough(
+        Changed |= maybeRewriteToFallthrough(
             MI, MBB, MF, MFI, MRI, TII, WebAssembly::FALLTHROUGH_RETURN_VOID,
             WebAssembly::INSTRUCTION_LIST_END);
         break;