[WebAssembly] Reduce redundancy in tests

[sbc100]

Summary

Add a simple start entry point input file and have the tests
reference that rather than duplicating these.

This allows more tests to be pure .test files rather than
.ll.

[ncw]

Looks nice and harmless.

[ruiu]

LGTM

test/wasm/Inputs/start.ll

+target triple = "wasm32-unknown-unknown-wasm"
+
+define void @_start() local_unnamed_addr {
+entry:
+  ret void
+}

test/wasm/import-memory.test

-# RUN: llc -filetype=obj %p/Inputs/ret32.ll -o %t.ret32.o
-# RUN: lld -flavor wasm -entry ret32 --import-memory -o %t.wasm %t.ret32.o
+# RUN: llc -filetype=obj %p/Inputs/start.ll -o %t.start.o
+# RUN: lld -flavor wasm --import-memory -o %t.wasm %t.start.o
 # RUN: obj2yaml %t.wasm | FileCheck %s
 
 # Verify the --import-memory flag creates a memory import
 
 # CHECK:       - Type:            IMPORT
 # CHECK-NEXT:    Imports:
 # CHECK-NEXT:      - Module:          env
 # CHECK-NEXT:        Field:           memory
 # CHECK-NEXT:        Kind:            MEMORY
 # CHECK-NEXT:        Memory:
 # CHECK-NEXT:          Initial:         0x00000002

test/wasm/invalid-stack-size.ll

-; RUN: llc -filetype=obj %s -o %t.o
-; RUN: not lld -flavor wasm -o %t.wasm -z stack-size=1 %t.o 2>&1 | FileCheck %s
-
-target triple = "wasm32-unknown-unknown-wasm"
-
-define i32 @_start() local_unnamed_addr #1 {
-entry:
-  ret i32 0
-}
-
-; CHECK: error: stack size must be 16-byte aligned

test/wasm/invalid-stack-size.test

+; RUN: llc -filetype=obj %p/Inputs/start.ll -o %t.o
+; RUN: not lld -flavor wasm -o %t.wasm -z stack-size=1 %t.o 2>&1 | FileCheck %s
+
+; CHECK: error: stack size must be 16-byte aligned

test/wasm/load-undefined.ll

-; Verify that the -u / --undefined option is able to pull in symbols from
-; an archive, and doesn't error when uses to pull in a symbol already loaded.
-;
-; RUN: llc -filetype=obj %S/Inputs/ret64.ll -o %t.o
-; RUN: llc -filetype=obj %S/Inputs/ret32.ll -o %t2.o
-; RUN: llc -filetype=obj %s -o %t3.o
-; RUN: llvm-ar rcs %t2.a %t2.o
-; RUN: lld -flavor wasm %t3.o %t2.a %t.o -o %t.wasm -u ret32 --undefined ret64
-; RUN: obj2yaml %t.wasm | FileCheck %s
-
-target triple = "wasm32-unknown-unknown-wasm"
-
-define i32 @_start() local_unnamed_addr {
-entry:
-  ret i32 1
-}
-
-; CHECK:        - Type:            EXPORT
-; CHECK-NEXT:     Exports:
-; CHECK-NEXT:       - Name:            memory
-; CHECK-NEXT:         Kind:            MEMORY
-; CHECK-NEXT:         Index:           0
-; CHECK-NEXT:       - Name:            _start
-; CHECK-NEXT:         Kind:            FUNCTION
-; CHECK-NEXT:         Index:           0
-; CHECK-NEXT:       - Name:            ret32
-; CHECK-NEXT:         Kind:            FUNCTION
-; CHECK-NEXT:         Index:           1
-; CHECK-NEXT:       - Name:            ret64
-; CHECK-NEXT:         Kind:            FUNCTION
-; CHECK-NEXT:         Index:           2
-; CHECK-NEXT:       - Name:            __heap_base
-; CHECK-NEXT:         Kind:            GLOBAL
-; CHECK-NEXT:         Index:           1
-; CHECK-NEXT:   - Type:
-
-
-; Verify that referencing a symbol that doesn't exist won't work
-; RUN: not lld -flavor wasm %t3.o -o %t.wasm -u symboldoesnotexist 2>&1 | FileCheck -check-prefix=CHECK-UNDEFINED1 %s
-; CHECK-UNDEFINED1: error: undefined symbol: symboldoesnotexist
-
-; RUN: not lld -flavor wasm %t3.o -o %t.wasm --undefined symboldoesnotexist --allow-undefined 2>&1 | FileCheck -check-prefix=CHECK-UNDEFINED2 %s
-; CHECK-UNDEFINED2: function forced with --undefined not found: symboldoesnotexist

test/wasm/load-undefined.test

+; Verify that the -u / --undefined option is able to pull in symbols from
+; an archive, and doesn't error when uses to pull in a symbol already loaded.
+;
+; RUN: llc -filetype=obj %S/Inputs/ret64.ll -o %t.o
+; RUN: llc -filetype=obj %S/Inputs/ret32.ll -o %t2.o
+; RUN: llc -filetype=obj %S/Inputs/start.ll -o %t.start.o
+; RUN: llvm-ar rcs %t2.a %t2.o
+; RUN: lld -flavor wasm %t.start.o %t2.a %t.o -o %t.wasm -u ret32 --undefined ret64
+; RUN: obj2yaml %t.wasm | FileCheck %s
+
+; CHECK:        - Type:            EXPORT
+; CHECK-NEXT:     Exports:
+; CHECK-NEXT:       - Name:            memory
+; CHECK-NEXT:         Kind:            MEMORY
+; CHECK-NEXT:         Index:           0
+; CHECK-NEXT:       - Name:            _start
+; CHECK-NEXT:         Kind:            FUNCTION
+; CHECK-NEXT:         Index:           0
+; CHECK-NEXT:       - Name:            ret32
+; CHECK-NEXT:         Kind:            FUNCTION
+; CHECK-NEXT:         Index:           1
+; CHECK-NEXT:       - Name:            ret64
+; CHECK-NEXT:         Kind:            FUNCTION
+; CHECK-NEXT:         Index:           2
+; CHECK-NEXT:       - Name:            __heap_base
+; CHECK-NEXT:         Kind:            GLOBAL
+; CHECK-NEXT:         Index:           1
+; CHECK-NEXT:   - Type:
+
+
+; Verify that referencing a symbol that doesn't exist won't work
+; RUN: not lld -flavor wasm %t.start.o -o %t.wasm -u symboldoesnotexist 2>&1 | FileCheck -check-prefix=CHECK-UNDEFINED1 %s
+; CHECK-UNDEFINED1: error: undefined symbol: symboldoesnotexist
+
+; RUN: not lld -flavor wasm %t.start.o -o %t.wasm --undefined symboldoesnotexist --allow-undefined 2>&1 | FileCheck -check-prefix=CHECK-UNDEFINED2 %s
+; CHECK-UNDEFINED2: function forced with --undefined not found: symboldoesnotexist

test/wasm/strip-debug.test

-RUN: llc -filetype=obj %p/Inputs/ret32.ll -o %t.ret32.o
-RUN: lld -flavor wasm --strip-debug --entry=ret32 -o %t.wasm %t.ret32.o
+RUN: llc -filetype=obj %p/Inputs/start.ll -o %t.start.o
+RUN: lld -flavor wasm --strip-debug -o %t.wasm %t.start.o
 RUN: obj2yaml %t.wasm | FileCheck %s
 
 # Check that there is no name section
 CHECK-NOT:   Name:    name