[NFC] Fix help text for tools that emit binary (#7398)

Our tools all stated that if -o is not provided, we write to stdout by
default. But that is not true - we do nothing in that case. I believe the
rationale is that we write text to stdout by default in say wasm2js, but
for wasm-opt etc. we don't want to write binary to stdout (as that is
dangerous).

Author: kripken

src/tools/wasm-as.cpp

@@ -44,7 +44,7 @@ int main(int argc, const char* argv[]) {
   options
     .add("--output",
          "-o",
-         "Output file (stdout if not specified)",
+         "Output file",
          WasmAsOption,
          Options::Arguments::One,
          [](Options* o, const std::string& argument) {

src/tools/wasm-ctor-eval.cpp

@@ -1374,7 +1374,7 @@ int main(int argc, const char* argv[]) {
   options
     .add("--output",
          "-o",
-         "Output file (stdout if not specified)",
+         "Output file",
          WasmCtorEvalOption,
          Options::Arguments::One,
          [](Options* o, const std::string& argument) {

src/tools/wasm-merge.cpp

@@ -590,7 +590,7 @@ Input source maps can be specified by adding an -ism option right after the modu
   options
     .add("--output",
          "-o",
-         "Output file (stdout if not specified)",
+         "Output file",
          WasmMergeOption,
          Options::Arguments::One,
          [](Options* o, const std::string& argument) {

src/tools/wasm-metadce.cpp

@@ -423,7 +423,7 @@ int main(int argc, const char* argv[]) {
   options
     .add("--output",
          "-o",
-         "Output file (stdout if not specified)",
+         "Output file",
          WasmMetaDCEOption,
          Options::Arguments::One,
          [](Options* o, const std::string& argument) {

src/tools/wasm-opt.cpp

@@ -99,7 +99,7 @@ int main(int argc, const char* argv[]) {
   options
     .add("--output",
          "-o",
-         "Output file (stdout if not specified)",
+         "Output file",
          WasmOptOption,
          Options::Arguments::One,
          [](Options* o, const std::string& argument) {

test/lit/help/wasm-as.test

@@ -10,7 +10,7 @@
 ;; CHECK-NEXT: wasm-as options:
 ;; CHECK-NEXT: ----------------
 ;; CHECK-NEXT:
-;; CHECK-NEXT:   --output,-o                          Output file (stdout if not specified)
+;; CHECK-NEXT:   --output,-o                          Output file
 ;; CHECK-NEXT:
 ;; CHECK-NEXT:   --validate,-v                        Control validation of the output module
 ;; CHECK-NEXT:

test/lit/help/wasm-ctor-eval.test

@@ -9,7 +9,7 @@
 ;; CHECK-NEXT: wasm-ctor-eval options:
 ;; CHECK-NEXT: -----------------------
 ;; CHECK-NEXT:
-;; CHECK-NEXT:   --output,-o                          Output file (stdout if not specified)
+;; CHECK-NEXT:   --output,-o                          Output file
 ;; CHECK-NEXT:
 ;; CHECK-NEXT:   --emit-text,-S                       Emit text instead of binary for the
 ;; CHECK-NEXT:                                        output file

test/lit/help/wasm-merge.test

@@ -25,7 +25,7 @@
 ;; CHECK-NEXT: wasm-merge options:
 ;; CHECK-NEXT: -------------------
 ;; CHECK-NEXT:
-;; CHECK-NEXT:   --output,-o                          Output file (stdout if not specified)
+;; CHECK-NEXT:   --output,-o                          Output file
 ;; CHECK-NEXT:
 ;; CHECK-NEXT:   --input-source-map,-ism              Consume source maps from the specified
 ;; CHECK-NEXT:                                        files

test/lit/help/wasm-metadce.test

@@ -51,8 +51,7 @@
 ;; CHECK-NEXT: wasm-opt options:
 ;; CHECK-NEXT: -----------------
 ;; CHECK-NEXT:
-;; CHECK-NEXT:   --output,-o                                   Output file (stdout if not
-;; CHECK-NEXT:                                                 specified)
+;; CHECK-NEXT:   --output,-o                                   Output file
 ;; CHECK-NEXT:
 ;; CHECK-NEXT:   --input-source-map,-ism                       Consume source map from the
 ;; CHECK-NEXT:                                                 specified file

test/lit/help/wasm-opt.test

@@ -9,8 +9,7 @@
 ;; CHECK-NEXT: wasm-opt options:
 ;; CHECK-NEXT: -----------------
 ;; CHECK-NEXT:
-;; CHECK-NEXT:   --output,-o                                   Output file (stdout if not
-;; CHECK-NEXT:                                                 specified)
+;; CHECK-NEXT:   --output,-o                                   Output file
 ;; CHECK-NEXT:
 ;; CHECK-NEXT:   --emit-text,-S                                Emit text instead of binary for
 ;; CHECK-NEXT:                                                 the output file