Fix script.test_fcoverage_mapping (#24973)

This is not really the intent of what -sSTRICT was to be about, but this
fixes the test at least.

Author: juj

system/lib/compiler-rt/lib/profile/InstrProfilingPort.h

@@ -54,7 +54,7 @@
 #endif
 
 #define COMPILER_RT_MAX_HOSTLEN 128
-#if defined(__ORBIS__) || defined(__wasi__)
+#if defined(__ORBIS__) || defined(__wasi__) || defined(__EMSCRIPTEN__)
 #define COMPILER_RT_GETHOSTNAME(Name, Len) ((void)(Name), (void)(Len), (-1))
 #else
 #define COMPILER_RT_GETHOSTNAME(Name, Len) lprofGetHostName(Name, Len)

test/code_size/test_codesize_hello_dylink_all.json

@@ -1,7 +1,7 @@
 {
   "a.out.js": 246665,
-  "a.out.nodebug.wasm": 597809,
-  "total": 844474,
+  "a.out.nodebug.wasm": 597720,
+  "total": 844385,
   "sent": [
     "IMG_Init",
     "IMG_Load",

tools/system_libs.py

@@ -942,7 +942,7 @@ class libcompiler_rt(MTLibrary, SjLjLibrary):
   # restriction soon: https://reviews.llvm.org/D71738
   force_object_files = True
 
-  cflags = ['-fno-builtin', '-DNDEBUG', '-DCOMPILER_RT_HAS_UNAME=1', '-DCOMPILER_RT_HAS_ATOMICS=1']
+  cflags = ['-fno-builtin', '-DNDEBUG', '-DCOMPILER_RT_HAS_ATOMICS=1']
   src_dir = 'system/lib/compiler-rt/lib/builtins'
   profile_src_dir = 'system/lib/compiler-rt/lib/profile'
   includes = ['system/lib/libc', 'system/lib/compiler-rt/include']