Missing stdbool.h

```c
#pragma ktcc module MyModule
#pragma ktcc package com.soywiz.test

#include
#include

typedef struct {
bool a; // <----------
union {
float f;
long int l;
} u;
} A;

int main() {
A a = {1};
return 0;
}
```

```
IllegalStateException: Can't find file=stdbool.h, kind=GLOBAL (in finalIncludeFolders=[])
at Object.captureStack (https://korlibs.github.io/ktcc/kotlin.js:39406:15)
at IllegalStateException.Exception [as constructor] (https://korlibs.github.io/ktcc/kotlin.js:39745:14)
at IllegalStateException.RuntimeException [as constructor] (https://korlibs.github.io/ktcc/kotlin.js:39771:17)
at IllegalStateException [as constructor] (https://korlibs.github.io/ktcc/kotlin.js:39811:24)
at IllegalStateException_init_0 (https://korlibs.github.io/ktcc/kotlin.js:39822:29)
at PreprocessorContext.includeProvider (https://korlibs.github.io/ktcc/ktcc.js:2264:15)
at CPreprocessor.tryGroupPart_k9acdb$ (https://korlibs.github.io/ktcc/ktcc.js:13865:49)
at CPreprocessor.tryGroup_k9acdb$ (https://korlibs.github.io/ktcc/ktcc.js:13990:35)
at CPreprocessor.preprocess_ue1dxp$ (https://korlibs.github.io/ktcc/ktcc.js:13996:10)
at CPreprocessor.preprocess (https://korlibs.github.io/ktcc/ktcc.js:13440:10)
```

Start with the CPreprocessor and PreprocessorContext.includeProvider entries in the stack trace, then reproduce the supplied sample with . Trace how global headers are resolved and verify that the sample no longer fails with “Can’t find file=stdbool.h”; no test file is named in the issue.

Written by the indexing model from the issue text.