PPC/s390: updating the macros to s390x and PPC64 to match our supporting platforms.

Change-Id: Ic1f112ff47040024bc416a43867ddff08d51246c
Reviewed-on: https://chromium-review.googlesource.com/c/1475333Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#59662}

src/wasm/jump-table-assembler.cc

@@ -136,7 +136,7 @@ void JumpTableAssembler::NopBytes(int bytes) {
   }
 }
 
-#elif V8_TARGET_ARCH_S390
+#elif V8_TARGET_ARCH_S390X
 void JumpTableAssembler::EmitLazyCompileJumpSlot(uint32_t func_index,
                                                  Address lazy_compile_target) {
   // Load function index to r7. 6 bytes
@@ -184,7 +184,7 @@ void JumpTableAssembler::NopBytes(int bytes) {
   }
 }
 
-#elif V8_TARGET_ARCH_PPC
+#elif V8_TARGET_ARCH_PPC64
 void JumpTableAssembler::EmitLazyCompileJumpSlot(uint32_t func_index,
                                                  Address lazy_compile_target) {
   // Load function index to register. max 5 instrs