[WebAssembly] Fixed missing "global" symbol type in AsmParser.

Summary:
These are emitted by the wasm backend for e.g.
__stack_pointer@GLOBAL which previously wasn't accepted by the
assembler.

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, llvm-commits, sunfish

Differential Revision: https://reviews.llvm.org/D52911

llvm-svn: 343830

Author: aardappel

llvm/lib/MC/MCExpr.cpp

@@ -419,6 +419,7 @@ MCSymbolRefExpr::getVariantKindForName(StringRef Name) {
     .Case("hi8", VK_AVR_HI8)
     .Case("hlo8", VK_AVR_HLO8)
     .Case("function", VK_WebAssembly_FUNCTION)
+    .Case("global", VK_WebAssembly_GLOBAL)
     .Case("typeindex", VK_WebAssembly_TYPEINDEX)
     .Case("gotpcrel32@lo", VK_AMDGPU_GOTPCREL32_LO)
     .Case("gotpcrel32@hi", VK_AMDGPU_GOTPCREL32_HI)

llvm/test/MC/WebAssembly/basic-assembly.s

@@ -47,6 +47,7 @@ test0:
     #i32x4.trunc_s/f32x4:sat
     i32.trunc_s/f32
     #i32.trunc_s:sat/f32
+    get_global	__stack_pointer@GLOBAL
     end_function
 
 
@@ -87,4 +88,5 @@ test0:
 # CHECK-NEXT:      get_local   5
 # CHECK-NEXT:      f32x4.add
 # CHECK-NEXT:      i32.trunc_s/f32
+# CHECK-NEXT:      get_global	__stack_pointer@GLOBAL
 # CHECK-NEXT:      end_function