[WebAssembly] Fix validation of start function

The check for valid start function was inverted.  Added a new
test in test/Object to check this case and fixed the existing
tests in for ObjectYAML.

Differential Revision: https://reviews.llvm.org/D32986

llvm-svn: 302560
diff --git a/llvm/test/ObjectYAML/wasm/function_section.yaml b/llvm/test/ObjectYAML/wasm/function_section.yaml
index 39e6b75..571b762 100644
--- a/llvm/test/ObjectYAML/wasm/function_section.yaml
+++ b/llvm/test/ObjectYAML/wasm/function_section.yaml
@@ -4,9 +4,7 @@
   Version:         0x00000001
 Sections:
   - Type:            FUNCTION
-    FunctionTypes:   
-      - 1
-      - 0
+    FunctionTypes: [ 1, 0 ]
 ...
 # CHECK: --- !WASM
 # CHECK: FileHeader: