[WebAssembly] Remove unneeded --no-gc-sections flag from tests. NFC.

[ruiu]

LGTM

test/wasm/call-indirect.ll

 ; RUN: llc -filetype=obj %p/Inputs/call-indirect.ll -o %t2.o
 ; RUN: llc -filetype=obj %s -o %t.o
-; RUN: wasm-ld -no-gc-sections --check-signatures -o %t.wasm %t2.o %t.o
+; RUN: wasm-ld --check-signatures -o %t.wasm %t2.o %t.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 ; bitcode generated from the following C code:
 ; int foo(void) { return 1; }
 ; int (*indirect_func)(void) = &foo;
 ; void _start(void) { indirect_func(); }
 
 target triple = "wasm32-unknown-unknown-wasm"

test/wasm/comdats.ll

 ; RUN: llc -filetype=obj -mtriple=wasm32-unknown-uknown-wasm %p/Inputs/comdat1.ll -o %t1.o
 ; RUN: llc -filetype=obj -mtriple=wasm32-unknown-uknown-wasm %p/Inputs/comdat2.ll -o %t2.o
 ; RUN: llc -filetype=obj -mtriple=wasm32-unknown-uknown-wasm %s -o %t.o
-; RUN: wasm-ld -no-gc-sections --check-signatures -o %t.wasm %t.o %t1.o %t2.o
+; RUN: wasm-ld --check-signatures -o %t.wasm %t.o %t1.o %t2.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 target triple = "wasm32-unknown-unknown-wasm"
 
 declare i32 @inlineFn()
 
 define void @_start() local_unnamed_addr {
 entry: