[libc] Clean up errno header usage in all remaining math/smoke tests. (#157565)

This is a follow-up to #157517, which fixes the remaining math/smoke
tests, and changes them to only include `hdr/errno_macros.h`, as the
tests just need the errno values to pass into `EXPECT_MATH_ERRO` macro.
A couple non-mechanical changes include:

* slightly better test coverage for some exp/log tests -- that actually
validates that errno is set to `EDOM` or `ERANGE` for certain inputs;
* explicit inclusion of `src/__support/libc_errno.h` in
RoundToIntegerTest template, which still needs to be fixed.

With this change there's a single libc_errno usage left:
```
$ grep -lrnH "libc_errno.h" test/src/math/smoke
test/src/math/smoke/RoundToIntegerTest.h
```

Author: vonosmas

libc/test/src/math/smoke/CMakeLists.txt

@@ -9,8 +9,8 @@
 #ifndef LLVM_LIBC_TEST_SRC_MATH_FMODTEST_H
 #define LLVM_LIBC_TEST_SRC_MATH_FMODTEST_H
 
+#include "hdr/errno_macros.h"
 #include "src/__support/FPUtil/FEnvImpl.h"
-#include "src/__support/libc_errno.h"
 #include "test/UnitTest/FEnvSafeTest.h"
 #include "test/UnitTest/FPMatcher.h"
 #include "test/UnitTest/Test.h"

libc/test/src/math/smoke/FModTest.h

@@ -12,6 +12,7 @@
 #include "src/__support/CPP/algorithm.h"
 #include "src/__support/FPUtil/FEnvImpl.h"
 #include "src/__support/FPUtil/FPBits.h"
+#include "src/__support/libc_errno.h"
 #include "test/UnitTest/FEnvSafeTest.h"
 #include "test/UnitTest/FPMatcher.h"
 #include "test/UnitTest/Test.h"

libc/test/src/math/smoke/RoundToIntegerTest.h

@@ -8,16 +8,13 @@
 
 #include "hdr/math_macros.h"
 #include "src/__support/FPUtil/FPBits.h"
-#include "src/__support/libc_errno.h"
 #include "src/math/atan2f.h"
 #include "test/UnitTest/FPMatcher.h"
 #include "test/UnitTest/Test.h"
 
 using LlvmLibcAtan2fTest = LIBC_NAMESPACE::testing::FPTest<float>;
 
 TEST_F(LlvmLibcAtan2fTest, SpecialNumbers) {
-  libc_errno = 0;
-
   EXPECT_FP_EQ_WITH_EXCEPTION(aNaN, LIBC_NAMESPACE::atan2f(sNaN, sNaN),
                               FE_INVALID);
   EXPECT_MATH_ERRNO(0);

libc/test/src/math/smoke/atan2f_test.cpp

@@ -6,15 +6,13 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/__support/libc_errno.h"
 #include "src/math/atanf16.h"
 #include "test/UnitTest/FPMatcher.h"
 #include "test/UnitTest/Test.h"
 
 using LlvmLibcAtanf16Test = LIBC_NAMESPACE::testing::FPTest<float16>;
 
 TEST_F(LlvmLibcAtanf16Test, SpecialNumbers) {
-  libc_errno = 0;
   EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::atanf16(aNaN));
   EXPECT_MATH_ERRNO(0);
 

libc/test/src/math/smoke/atanf16_test.cpp

@@ -8,7 +8,6 @@
 
 #include "hdr/math_macros.h"
 #include "src/__support/FPUtil/FPBits.h"
-#include "src/__support/libc_errno.h"
 #include "src/math/atanf.h"
 #include "test/UnitTest/FPMatcher.h"
 #include "test/UnitTest/Test.h"
@@ -18,7 +17,6 @@
 using LlvmLibcAtanfTest = LIBC_NAMESPACE::testing::FPTest<float>;
 
 TEST_F(LlvmLibcAtanfTest, SpecialNumbers) {
-  libc_errno = 0;
   EXPECT_FP_EQ_WITH_EXCEPTION(aNaN, LIBC_NAMESPACE::atanf(sNaN), FE_INVALID);
   EXPECT_MATH_ERRNO(0);
 

libc/test/src/math/smoke/atanf_test.cpp

@@ -6,16 +6,15 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "hdr/errno_macros.h"
 #include "src/__support/FPUtil/cast.h"
-#include "src/__support/libc_errno.h"
 #include "src/math/atanhf16.h"
 #include "test/UnitTest/FPMatcher.h"
 #include "test/UnitTest/Test.h"
 
 using LlvmLibcAtanhf16Test = LIBC_NAMESPACE::testing::FPTest<float16>;
 
 TEST_F(LlvmLibcAtanhf16Test, SpecialNumbers) {
-  libc_errno = 0;
   EXPECT_FP_EQ_WITH_EXCEPTION_ALL_ROUNDING(aNaN, LIBC_NAMESPACE::atanhf16(sNaN),
                                            FE_INVALID);
   EXPECT_MATH_ERRNO(0);

libc/test/src/math/smoke/atanhf16_test.cpp

@@ -6,9 +6,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "hdr/errno_macros.h"
 #include "hdr/math_macros.h"
 #include "src/__support/FPUtil/FPBits.h"
-#include "src/__support/libc_errno.h"
 #include "src/math/atanhf.h"
 #include "test/UnitTest/FPMatcher.h"
 #include "test/UnitTest/Test.h"
@@ -20,7 +20,6 @@ using LIBC_NAMESPACE::Sign;
 using LlvmLibcAtanhfTest = LIBC_NAMESPACE::testing::FPTest<float>;
 
 TEST_F(LlvmLibcAtanhfTest, SpecialNumbers) {
-  libc_errno = 0;
   EXPECT_FP_EQ_WITH_EXCEPTION(aNaN, LIBC_NAMESPACE::atanhf(sNaN), FE_INVALID);
   EXPECT_MATH_ERRNO(0);
   // TODO: Strengthen errno,exception checks and remove these assert macros

libc/test/src/math/smoke/atanhf_test.cpp

@@ -6,7 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/__support/libc_errno.h"
 #include "src/math/atanpif16.h"
 #include "test/UnitTest/FPMatcher.h"
 

libc/test/src/math/smoke/atanpif16_test.cpp

@@ -6,16 +6,14 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/__support/libc_errno.h"
+#include "hdr/errno_macros.h"
 #include "src/math/cosf16.h"
 #include "test/UnitTest/FPMatcher.h"
 #include "test/UnitTest/Test.h"
 
 using LlvmLibcCosf16Test = LIBC_NAMESPACE::testing::FPTest<float16>;
 
 TEST_F(LlvmLibcCosf16Test, SpecialNumbers) {
-  libc_errno = 0;
-
   EXPECT_FP_EQ_WITH_EXCEPTION(aNaN, LIBC_NAMESPACE::cosf16(sNaN), FE_INVALID);
   EXPECT_MATH_ERRNO(0);